Patellar Tendon Rupture
High-yield overview
Infrapatellar Rupture and Repair
under 40Typical age (younger than quad rupture)
greater than 1.2Insall-Salvati = patella alta
less than 5%Re-rupture after repair
Rupture patterns (by location)
Proximal (inferior pole)
PatternAvulsion from inferior pole of patella — most common site
TreatmentTransosseous tunnels / suture anchors
Mid-substance
PatternIntratendinous tear (often degenerate / tendinopathic)
TreatmentDirect end-to-end repair, usually augmented
Distal (tibial tubercle)
PatternAvulsion at tubercle; tubercle avulsion in adolescents
TreatmentAnchors / tunnel repair; ORIF if bony fragment
Critical Must-Knows
- Definition: Disruption of the patellar ligament linking the inferior pole of the patella to the tibial tubercle, abolishing the extensor mechanism
- Demographics: Typically males under 40; quadriceps tendon rupture is the disease of patients over 40
- Mechanism: Sudden eccentric quadriceps contraction against a flexed knee (landing from a jump, missed step) — most commonly at the inferior pole
- Diagnostic triad: palpable infrapatellar gap + loss of active knee extension (no straight-leg raise) + patella alta on lateral radiograph
- Management: Complete ruptures require early surgical repair — never managed conservatively
Clinical Pearls
- "Patella alta with Insall-Salvati greater than 1.2 is the hallmark radiographic sign
- "Ultrasound is a rapid bedside confirmatory test; MRI clarifies level and tissue quality
- "Bilateral or spontaneous rupture = systemic disease until proven otherwise
- "Outcomes are good but full power recovery takes 6-12 months; stiffness is the main complication
Clinical Imaging
Imaging Gallery
Exam Warning
Patella Alta (High riding patella) is the hallmark X-ray sign. Use the Insall-Salvati Ratio (Length of Tendon / Length of Patella). Normal is ~1.0. Greater than 1.2 = Alta. Rupture most commonly occurs at the inferior pole of the patella (Proximal end of tendon).
Mnemonic
T-PInsall-Salvati Ratio
| R | Ratio over 1.2 = Patella Alta (think patellar TENDON rupture) |
| R | Ratio under 0.8 = Patella Baja (think QUADRICEPS rupture, or over-tightened repair) |
| R | Restoring a normal ratio (about 1.0) is the intra-operative goal |
| R | Ratio over 1.2 = Patella Alta (think patellar TENDON rupture) |
| R | Ratio under 0.8 = Patella Baja (think QUADRICEPS rupture, or over-tightened repair) |
| R | Restoring a normal ratio (about 1.0) is the intra-operative goal |
Hook:The Tendon is Taller (alTa) when the patellar tendon is ruptured
Mnemonic
STRAIGHT LEGSystemic Risk Factors for Tendon Rupture
| S | Steroids (corticosteroid or anabolic) and local injection | H | Hyperparathyroidism (secondary, in CKD) |
| T | Tendinopathy (jumper's knee) and prior BTB graft harvest | T | Thyroid and other endocrinopathy |
| R | Renal failure (chronic) and dialysis | L | Lupus (SLE) |
| A | Arthritis — rheumatoid and other inflammatory | E | Endocrine — diabetes mellitus |
| I | Infection / immunosuppression | G | Gyrase inhibitors — fluoroquinolone antibiotics |
| G | Gout and crystal deposition |
| S | Steroids (corticosteroid or anabolic) and local injection | A | Arthritis — rheumatoid and other inflammatory | H | Hyperparathyroidism (secondary, in CKD) | E | Endocrine — diabetes mellitus |
| T | Tendinopathy (jumper's knee) and prior BTB graft harvest | I | Infection / immunosuppression | T | Thyroid and other endocrinopathy | G | Gyrase inhibitors — fluoroquinolone antibiotics |
| R | Renal failure (chronic) and dialysis | G | Gout and crystal deposition | L | Lupus (SLE) |
Hook:A weak tendon cannot hold a STRAIGHT LEG raise
Mnemonic
GAPDiagnostic Triad of Patellar Tendon Rupture
| G | Gap — palpable infrapatellar defect below the patella |
| A | Active extension lost — cannot perform a straight-leg raise / extensor lag |
| P | Patella alta — high-riding patella on lateral radiograph (Insall-Salvati over 1.2) |
| G | Gap — palpable infrapatellar defect below the patella |
| A | Active extension lost — cannot perform a straight-leg raise / extensor lag |
| P | Patella alta — high-riding patella on lateral radiograph (Insall-Salvati over 1.2) |
Hook:A ruptured tendon leaves a GAP
Overview & Epidemiology
Patellar tendon (more correctly patellar ligament) rupture is the least common of the three extensor-mechanism injuries, after patella fracture and quadriceps tendon rupture. It is the third most common extensor-mechanism disruption overall but the dominant one in younger, athletic patients.
Key epidemiological points:
- Predominantly males under 40 years, often athletic. Quadriceps tendon rupture is the corresponding injury in patients over 40.
- Almost always a complete rupture follows pre-existing tendinopathy — the tendon rarely fails when truly healthy.
- Up to roughly one-third of patients have a local risk factor (antecedent tendinopathy, jumper's knee, prior peritendinous corticosteroid injection, prior ACL bone–patellar tendon–bone harvest) or a systemic risk factor; systemic factors dominate in bilateral ruptures.
- Bilateral simultaneous rupture is rare and, when it occurs after low-energy trauma, signifies systemic disease (chronic renal failure, hyperparathyroidism, diabetes, SLE, rheumatoid arthritis, chronic corticosteroid or anabolic-steroid use, fluoroquinolone exposure).
Anatomy & Biomechanics
Patellar ligament — structure:
- A continuation of the central quadriceps tendon, running from the inferior pole of the patella to the tibial tubercle.
- Length approximately 4-6 cm; width approximately 25-30 mm; thickness approximately 5-7 mm.
- Blood supply is from the infrapatellar fat pad posteriorly and the peritendinous retinacular plexus anteriorly. There is a relatively hypovascular zone at the proximal third / inferior pole, which corresponds to the most common rupture site.
Biomechanics:
- The extensor mechanism transmits very high tensile loads — peak patellofemoral and tendon forces can reach multiples of body weight during jumping and stair descent.
- The patella acts as a fulcrum that increases the moment arm of the quadriceps; loss of patellar tendon continuity abolishes active terminal extension and the ability to lock the knee in stance.
Pathophysiology
- The classic mechanism is sudden eccentric quadriceps contraction against a flexed knee (landing from a jump, missing a step), with the knee usually flexed about 60 degrees at the moment of failure.
- Failure occurs when the applied eccentric load exceeds tendon tensile strength. In a healthy tendon this requires extreme force; in a degenerate tendon, ordinary activity (stumbling, rising from a chair) can suffice.
- Histologically, ruptured tendons typically show mucoid / angiofibroblastic degeneration (tendinosis) rather than acute inflammation, which explains the friable "mop-end" tissue found at surgery and the role of antecedent tendinopathy.
- Rupture most commonly occurs at the proximal insertion (inferior pole avulsion), less commonly mid-substance, and least commonly at the tibial tubercle.
- Systemic factors (corticosteroids, chronic renal failure with secondary hyperparathyroidism, diabetes, inflammatory arthropathy, fluoroquinolones) impair collagen quality and underlie spontaneous and bilateral ruptures.
Clinical Presentation
History:
- Sudden pop or giving way during eccentric loading (jump landing, missed step, fall), with immediate inability to weight-bear or extend the knee.
- Always ask about systemic risk factors and prior anterior knee symptoms (tendinopathy) or steroid/fluoroquinolone use.
Examination — the diagnostic triad:
- Palpable infrapatellar gap below the inferior pole of the patella.
- Loss of active knee extension — the patient cannot perform a straight-leg raise or hold the extended knee against gravity (extensor lag). Note: an intact medial/lateral retinaculum may permit weak, painful extension in a partial tear, which is a diagnostic trap.
- High-riding patella (patella alta) palpable proximally, often with a haemarthrosis.
Always examine the contralateral knee and screen other tendons (quadriceps, Achilles) if a systemic cause is suspected.
Investigations
Plain radiographs (first-line):
- Lateral view is key — shows patella alta and quantifies it with the Insall-Salvati ratio (tendon length / patella diagonal length; normal 0.8-1.2; over 1.2 = alta).
- The Caton-Deschamps index (articular surface to anterosuperior tibia / patellar articular length; normal about 1.0) is an alternative that is independent of patellar tendon length and is preferred when the tendon itself is abnormal or after TKA.
- Look for an avulsed bony fragment from the inferior pole or tubercle, and exclude patella fracture.
Ultrasound: rapid, dynamic, bedside confirmation of tendon discontinuity, gap size and partial-versus-complete tears; highly operator dependent.
MRI: the most sensitive modality. Defines the level of rupture (proximal/mid/distal), completeness, gap size, tissue quality and concomitant injury — most useful in equivocal, partial, chronic or atypical cases. Not required when the clinical triad is unequivocal.
Differential Diagnosis of Acute Loss of Knee Extension
Management
Complete patellar tendon rupture is a surgical injury — conservative treatment leaves a permanent extensor lag and severe functional disability. Only genuinely partial tears with intact active extension (preserved retinaculum, able to straight-leg raise) may be treated non-operatively in a brace with the knee in extension. The principles are: repair early, restore patellar height, augment friable tissue, and mobilise early to avoid stiffness.
Indication: complete rupture, presenting within 2-3 weeks before retraction and scarring set in.
Technique:
- Midline anterior incision; identify and debride the ragged tendon ends and the inferior pole.
- Place locking Krackow sutures (heavy non-absorbable, e.g. #5 / #2 high-strength) in each limb of the tendon, taking a 4-5 cm purchase.
- Reattach using 3 vertical transosseous patellar tunnels OR 2-3 suture anchors in the inferior pole. Biomechanically these are equivalent for ultimate load to failure; suture anchors show lower cyclic gap formation.
- Repair medial and lateral retinacular extensions of the tear.
- Confirm patellar height intra-operatively with a lateral image and compare with the contralateral side — avoid over-tightening.
Key Evidence
Extensor mechanism ruptures — contemporary review
Tandogan RN, Terzi E, Gomez-Barrena E, et al. • EFORT Open Rev (2022)
Key Findings:
- Native patellar tendon ruptures occur in younger patients than quadriceps tendon ruptures
- Up to one-third of patients have local or systemic risk factors; these are more frequent in bilateral disruptions
- Complete disruptions should be repaired surgically; augmentation is advised for poor tissue quality, chronic tears or defects
- High rates of return to work/sport are reported with re-rupture rates under 5%
- Extensor mechanism injuries after TKA have inferior outcomes and warrant augmentation in all cases
Clinical Implication: Repair early, augment friable or chronic tissue, and screen for systemic disease — especially with bilateral rupture.
Patellar tendon restoration — systematic review of repair vs reconstruction
Fortier LM, Adelstein JM, Sinkler MA, et al. • Eur J Orthop Surg Traumatol (2024)
Key Findings:
- 23 studies, 738 patients across acute, chronic, post-TKA and post-ACLR settings
- Acute repairs achieved mean post-operative Lysholm scores of 84 to 99.5
- In the primary setting, primary repair with and without augmentation gave comparable Lysholm scores
- Cerclage augmentation alone yielded the lowest Lysholm scores and should not be relied upon as the sole construct
- In post-TKA patients, allograft reconstruction (KSS 79-88) outperformed autograft (KSS 70)
Clinical Implication: Early primary repair gives excellent outcomes; for chronic and post-TKA cases, allograft reconstruction is favoured.
Suture anchor vs transosseous tunnel — biomechanical meta-analysis
Imbergamo C, Sequeira S, Bano J, et al. • Orthop J Sports Med (2022)
Key Findings:
- Systematic review and meta-analysis of 7 biomechanical studies, 128 cadaveric specimens (66 suture anchor, 62 transosseous)
- Suture anchor fixation produced significantly lower cyclic gap displacement than transosseous tunnels
- No significant difference in ultimate load to failure between the two techniques
- Both remain widely used and acceptable constructs in clinical practice
Clinical Implication: Suture anchors and transosseous tunnels are biomechanically equivalent for strength; anchors may resist gapping better.
Chronic patellar tendon reconstruction after TKA — graft comparison
Lamberti A, Balato G, Summa PP, et al. • Knee Surg Sports Traumatol Arthrosc (2016)
Key Findings:
- 21 chronic post-TKA reconstructions in three groups of 7 (Achilles allograft, quadriceps+semitendinosus autograft, full extensor mechanism allograft)
- Mean extensor lag improved from about 50 degrees to about 3 degrees; mean KSS rose from 44.7 to 78.9
- Achilles allograft (KSS 87.7) significantly outperformed autograft (KSS 70.0)
- Authors conclude Achilles tendon allograft should be considered the gold-standard repair for chronic post-TKA lesions
Clinical Implication: For chronic post-TKA patellar tendon loss, Achilles allograft with calcaneal block gives the best functional restoration.
Return to play after patellar tendon repair in professional athletes
Nguyen MT, Hsu WK • Phys Sportsmed (2019)
Key Findings:
- 103 professional baseball, basketball, American football and soccer athletes after patellar tendon repair
- 79 of 103 (76.7%) successfully returned to play
- American football athletes had the lowest return-to-play rate and the shortest adjusted careers
- Soccer athletes showed short-term performance decline that recovered to baseline by seasons 2-3
Clinical Implication: Even after successful repair, return to elite sport is not universal and is sport-dependent — counsel athletes accordingly.
Hamstring double-row reconstruction for post-TKA patellar tendon rupture
Akgun E, Emet A, Tepedelenlioglu E, et al. • Medicine (Baltimore) (2024)
Key Findings:
- 14 patients (mean age 68.1) with post-TKA patellar tendon rupture reconstructed using ipsilateral semitendinosus and gracilis double-row technique
- Median Caton-Deschamps index improved from 1.8 to 1.25 (p = 0.014)
- Median active knee-extension loss fell from 25 degrees to 5 degrees
- Tegner-Lysholm and Kujala scores significantly improved at mean 3.8-year follow-up
Clinical Implication: Hamstring autograft double-row is an effective autologous option for post-TKA distal patellar tendon rupture.
Complications
Complications of Patellar Tendon Repair
Controversies & Areas of Uncertainty
- Suture anchors vs transosseous tunnels. Biomechanically equivalent for ultimate load, with anchors showing less cyclic gap formation; clinical outcomes are similar. Choice remains surgeon preference and tissue quality, not high-level clinical evidence.
- Routine augmentation in acute repair. Augmentation (suture tape / cerclage) is intuitively protective and allows accelerated rehabilitation, but a systematic review found primary repair with and without augmentation gave comparable Lysholm scores in good-quality acute tears — so universal augmentation in healthy young tendon is debated, while it is clearly favoured for poor tissue, chronic and post-TKA cases.
- Timing thresholds. "Acute" (under 2-3 weeks) versus "chronic" is a useful heuristic, but the true point at which retraction mandates reconstruction varies with tissue quality rather than a fixed day count.
- Allograft vs autograft for chronic/post-TKA reconstruction. Achilles allograft gives the best comparative scores in post-TKA series, but allograft cost, availability and incorporation risk keep hamstring and quadriceps autograft techniques relevant, especially in younger patients and resource-limited settings.
- Accelerated vs protected rehabilitation. Early motion reduces the dominant complication (stiffness) but must be balanced against re-rupture risk; the optimal protocol, and how much augmentation should change it, is not standardised.
- Bilateral simultaneous rupture: staged vs single-stage repair. No comparative trials exist; the decision is individualised around rehabilitation feasibility, comorbidity and social support.
Guidelines, Registries & Global Practice
Global epidemiology
- Patellar tendon rupture is the rarest of the three extensor-mechanism injuries but predominates in active males under 40 worldwide; quadriceps tendon rupture predominates over 40.
- A substantial minority (up to roughly one-third) carry local or systemic risk factors; systemic disease underlies most bilateral ruptures across all populations.
Society guidance & consensus (side by side)
| Body / source | Position on patellar tendon rupture |
|---|---|
| AAOS (US) | No disease-specific guideline; consensus and review literature support early surgical repair of complete ruptures with anatomic restoration of patellar height. |
| BOA / BOAST (UK) | No dedicated BOAST; managed under knee/soft-tissue trauma principles — urgent diagnosis of extensor-mechanism disruption and timely surgical repair. |
| AO Foundation | Describes operative repair (transosseous suture / anchors) and augmentation techniques as standard for extensor-mechanism reattachment. |
| EFORT (Europe) | EFORT Open Reviews synthesis (Tandogan 2022) endorses early surgical repair, augmentation for poor/chronic tissue, and allograft for complex/post-TKA reconstruction. |
There is broad international consensus rather than divergent national guidelines: complete rupture is a surgical injury, repaired early, with augmentation and reconstruction reserved for poor tissue, chronic and post-arthroplasty cases.
Registry note
- No dedicated patellar tendon rupture registry exists. Relevant signal comes from arthroplasty registries (NJR, AJRR, AOANJRR), where extensor-mechanism disruption is a recognised, function-limiting complication after TKA that drives revision and poorer patient-reported outcomes — the population in which reconstruction (and allograft) is most often required.
High- vs limited-resource practice variation
- Well-resourced settings: ready access to MRI, suture anchors, suture-tape internal brace and tissue-bank allograft (Achilles / full extensor-mechanism) for complex reconstruction.
- Limited-resource settings: reliance on clinical diagnosis and plain radiographs, transosseous tunnel repair with heavy suture and stainless-steel cerclage wire, and autograft (hamstring, contralateral BTB) where allograft is unavailable or unaffordable — all of which deliver good outcomes when applied to the correct indication.
References
According to PubMed, the evidence cards above are drawn from the following verified sources:
- Tandogan RN, et al. Extensor mechanism ruptures. EFORT Open Rev. 2022. PMID 35638613. DOI
- Fortier LM, et al. Patellar tendon restoration techniques: a systematic review. Eur J Orthop Surg Traumatol. 2024. PMID 39212690. DOI
- Imbergamo C, et al. Failure rates of suture anchor vs transosseous tunnel for patellar tendon repair: meta-analysis. Orthop J Sports Med. 2022. PMID 36035892. DOI
- Lamberti A, et al. Surgical options for chronic patellar tendon rupture in TKA. Knee Surg Sports Traumatol Arthrosc. 2016. PMID 27815584. DOI
- Nguyen MT, Hsu WK. Performance-based outcomes following patellar tendon repair in professional athletes. Phys Sportsmed. 2019. PMID 31291548. DOI
- Akgun E, et al. Double-row hamstring reconstruction for patellar tendon rupture after TKA. Medicine (Baltimore). 2024. PMID 38669383. DOI
Exam Viva Scenarios
Use these scenarios to practise clinical reasoning and management decisions
CLINICAL SCENARIOStandard
Scenario 1: Acute Patellar Tendon Rupture - Standard Operative Management
CLINICAL PROMPT
"A 30-year-old basketball player lands from a jump and feels a pop in his knee. He has immediate swelling and cannot stand up. On examination, there is a palpable defect below the patella and he cannot perform a straight leg raise. X-ray shows an Insall-Salvati ratio of 1.5. How do you assess and manage this injury?"
PRACTICAL APPROACH
This is an acute patellar tendon rupture. The diagnosis is confirmed clinically by the triad of (1) palpable infrapatellar gap, (2) loss of active knee extension (cannot straight leg raise), and (3) patella alta on X-ray (Insall-Salvati ratio 1.5, normal is 0.8-1.2, greater than 1.2 indicates alta from tendon rupture). The mechanism (landing from jump, eccentric quadriceps contraction against flexed knee) and age (30, younger than typical quad rupture which is over 40) are consistent with patellar tendon rupture. Assessment: The Insall-Salvati ratio is measured as tendon length divided by patella length on lateral X-ray - his ratio of 1.5 confirms high-riding patella (alta) from loss of tendon continuity. I would examine for systemic risk factors (unlikely in young athlete but ask about steroid use, rheumatoid arthritis, renal disease, lupus) and examine the contralateral knee (bilateral rupture is rare but possible if systemic pathology). MRI is usually not required if diagnosis is clinically clear, but can be helpful to assess the exact location of rupture (proximal avulsion from inferior pole is most common, mid-substance, or distal tibial tubercle), identify any concomitant injuries (meniscal tears, ACL if severe trauma), and plan surgery. Management is operative repair - this is mandatory for complete patellar tendon rupture as conservative management results in permanent loss of extensor mechanism function. Timing: ideally within 7-10 days (acute repair less than 2-3 weeks has significantly better outcomes than delayed/chronic repair as per Rose 2007 JBJS - allows direct repair before tendon retraction and scarring). Surgical technique: Midline incision over the patellar tendon. Identify the rupture site (usually proximal avulsion from inferior pole of patella). Prepare the bone surface by debriding/freshening the inferior pole of patella (decorticate to bleeding bone). Repair options: (1) Transosseous tunnels - drill 3 parallel vertical tunnels through the patella from inferior to superior pole, place heavy non-absorbable sutures (Ethibond #5 or FiberWire #2) in Krackow locking configuration through the tendon ends (4-5cm purchase for security), pass sutures through the tunnels and tie over the superior pole or anteriorly with a bone bridge, or (2) Suture anchors - place 2-3 anchors in the inferior pole of patella, attach sutures to tendon in Krackow pattern. Evidence shows equivalent outcomes between transosseous and anchors (Rose 2007). Augmentation (Internal Brace): Because patellar tendon tears are typically 'mop-end' degenerative tears with ragged tissue quality, I would use augmentation to protect the repair and allow earlier safe mobilization. Options include cerclage wire (18-gauge) or suture tape (FiberTape, InternalBrace) passed through a tibial tubercle tunnel and around/through the patella or quadriceps tendon proximally, creating a tension band that offloads the repair during early flexion. This is increasingly standard practice. Intraoperative check: Use C-arm lateral X-ray to confirm patellar height is restored (compare to contralateral knee) - must avoid overtightening which causes patella baja (Insall-Salvati less than 0.8) leading to anterior knee pain, patellofemoral wear, and limited flexion. Target is to restore normal ratio around 1.0. Also repair any medial or lateral retinacular extensions of the tear. Post-operative rehabilitation: Hinged knee brace locked in extension for ambulation, full weight-bearing allowed in extension (the augmentation protects the repair), early ROM starting at 0-45° or 0-60° for first 2-4 weeks (depending on repair security and augmentation), progressive flexion advancement, avoid aggressive flexion beyond 90° for 6 weeks, quadriceps strengthening begins early with isometrics then progressive resistance, return to sport at 6-12 months depending on power recovery. Expected outcomes: Good results with early repair, but full quadriceps power recovery takes 6-12 months and 10-20% residual weakness is common (Rose 2007). Return to pre-injury sport level is 70-80%. Key message: restore anatomy (patella height), protect repair with augmentation, allow early motion to prevent stiffness (major complication risk), manage expectations about power recovery.
KEY CLINICAL POINTS
Diagnostic triad: palpable infrapatellar gap + loss of active extension + patella alta (Insall-Salvati greater than 1.2)
Surgical repair is mandatory for complete rupture within 7-10 days ideally (less than 2-3 weeks)
Technique: transosseous tunnels or suture anchors with Krackow configuration
Augmentation (cerclage wire or suture tape) protects repair and allows early motion
Restore patella height intraoperatively (avoid overtightening = patella baja)
Younger age group (under 40) vs quadriceps rupture (over 40)
COMMON PITFALLS
Overtightening the repair causing patella baja (Insall-Salvati less than 0.8) - leads to pain, wear, limited flexion
Conservative management for complete rupture - results in permanent extensor lag and disability
Missing tibial tubercle avulsion fracture in adolescents (skeletally immature) - treat with ORIF of avulsion
Delayed repair beyond 2-3 weeks - becomes chronic/neglected rupture requiring complex reconstruction
Not using augmentation in mop-end degenerative tears - higher re-rupture risk (5%) with aggressive early flexion
FURTHER QUESTIONS
"How do you measure the Insall-Salvati ratio?"
"What is the blood supply to the patellar tendon?"
"What are the risk factors for patellar tendon rupture?"
"How would you manage a chronic neglected rupture presenting at 6 months?"
"What is the difference between patellar tendon rupture and quadriceps rupture in terms of patient demographics?"
CLINICAL SCENARIOChallenging
Scenario 2: Bilateral Simultaneous Patellar Tendon Rupture - Systemic Risk Factors
CLINICAL PROMPT
"You are called to the Emergency Department to see a 42-year-old man who has presented unable to walk after a fall down stairs. He reports that both knees 'gave way' simultaneously as he tried to catch himself. On examination, he has bilateral palpable infrapatellar gaps and cannot perform a straight leg raise on either side. He is obese (BMI 36) and on further history reveals he has had a renal transplant 3 years ago and is on long-term immunosuppression (prednisone 10mg daily, tacrolimus). He also has chronic kidney disease stage 3 and secondary hyperparathyroidism. X-rays of both knees show bilateral patella alta with Insall-Salvati ratios of 1.4 on the right and 1.6 on the left. How do you approach this patient's management and what are the specific considerations?"
PRACTICAL APPROACH
This is a bilateral simultaneous patellar tendon rupture, which is a rare but well-recognized presentation that should immediately alert me to systemic risk factors predisposing to tendon degeneration. Bilateral ruptures are uncommon (less than 5% of all patellar tendon ruptures) and almost always occur in the context of systemic disease, whereas unilateral ruptures are typically traumatic in otherwise healthy active young patients. This patient has multiple significant risk factors: (1) Chronic corticosteroid use (prednisone 10mg daily for 3 years post-transplant) - steroids cause tendon degeneration, impaired collagen synthesis, and increased rupture risk; (2) Chronic renal disease and secondary hyperparathyroidism - causes calcium deposition in tendons, metabolic bone disease, and tendon weakening; (3) Immunosuppression (tacrolimus) - may contribute to impaired tissue healing; (4) Obesity (BMI 36) - increased mechanical load on tendons. The combination of these factors has caused bilateral tendon degeneration leading to spontaneous rupture with minimal trauma (fall down stairs). Assessment and investigations: Confirm bilateral patellar tendon ruptures clinically (bilateral palpable gaps, loss of active extension bilaterally) and radiologically (bilateral patella alta). Beyond standard X-rays, I would obtain blood tests: renal function (creatinine, eGFR), parathyroid hormone (PTH) level to quantify hyperparathyroidism, calcium, phosphate, vitamin D, and HbA1c (check for diabetes which is another risk factor). I would also examine other tendon sites (Achilles bilaterally, quadriceps) to assess for generalized tendinopathy. MRI of both knees can help identify the exact rupture location and assess tissue quality, though diagnosis is clinically clear. Multidisciplinary involvement: This is not a straightforward athletic injury - I would involve the patient's nephrologist and transplant team to optimize his medical management perioperatively. Discussion points include: Can steroid dose be reduced postoperatively? (Likely not immediately given transplant rejection risk, but perhaps tapered over months.) How to manage immunosuppression perioperatively to balance infection risk vs rejection risk? Is the secondary hyperparathyroidism adequately treated? (May need cinacalcet or parathyroidectomy if severe, but not acutely.) Surgical management - staging decision: The critical question is whether to repair both knees simultaneously (single-stage) or stage the repairs (repair one knee, then the other after 2-3 weeks). Arguments for single-stage bilateral repair: (1) Single anesthetic exposure (important given renal disease and obesity), (2) Patient convenience (one hospitalization, one recovery period), (3) Psychological benefit (both injuries addressed together). Arguments for staged repair: (1) Post-operative rehabilitation is extremely difficult with bilateral repairs - patient cannot weight-bear on either leg initially, requires wheelchair or bilateral crutches with very limited mobility, high risk of complications (DVT, pressure sores, deconditioning); (2) Single-stage has very high stiffness risk (15-20%) due to bilateral immobility; (3) Anesthetic risk with prolonged bilateral surgery in high-risk patient (renal disease, obesity); (4) If complications occur in one knee (infection, re-rupture), staged approach allows salvage of at least one knee. My recommendation: In most cases, I would favor staged repair with 2-3 week interval. Repair the more symptomatic or more severely ruptured knee first (in this case, left knee with higher Insall-Salvati 1.6 suggesting more retraction), allow patient to mobilize weight-bearing on the un-operated side using crutches or walker, then repair the second knee 2-3 weeks later once the first repair is stable enough to allow touch-toe weight-bearing. However, if the patient is young, fit (despite obesity), and highly motivated with excellent social support (family to assist with ADLs during bilateral non-weight-bearing period), simultaneous bilateral repair can be considered. This patient's risk factors (age 42, obesity, renal disease) favor staging. Surgical technique: Same as for unilateral rupture but with particular emphasis on secure repair given poor tissue quality from steroid use and metabolic disease. I would use transosseous tunnels or suture anchors with Krackow technique, and DEFINITELY use augmentation (cerclage wire or suture tape) to protect the repair - the tissue quality will be poor (mop-end degenerative tears) and the patient's systemic factors impair healing. I would be meticulous about restoring patella height (avoid overtightening which is easier to do when tissue is degenerate). Consider using local tissue augmentation if available (turn-down flaps from quadriceps tendon). Post-operative management: For staged approach - first knee repaired, hinged brace locked in extension for ambulation, weight-bearing as tolerated on operated leg (the augmentation protects repair), patient mobilizes using walker or crutches bearing weight on non-operated leg, ROM 0-45° for 2 weeks then progressive, at 2-3 weeks when first repair is stable, proceed to repair second knee. After second surgery, patient has bilateral braces and is touch-toe weight-bearing bilaterally (very challenging), requires intensive physiotherapy, home modifications, family support. For simultaneous bilateral repair - patient is wheelchair-bound or using walking frame with bilateral touch-toe weight-bearing for 6 weeks, very high dependency, DVT prophylaxis essential (LMWH, intermittent pneumatic compression devices), aggressive chest physiotherapy given obesity and immobility, slow progressive rehabilitation. Prognosis and counseling: Worse than unilateral rupture in healthy patient. Steroid use and renal disease impair healing, obesity increases mechanical stress, risk of re-rupture is higher (10-15% vs 5% in healthy patients), permanent extensor lag more likely (20-30% vs 10-20%), return to functional independence is the goal rather than return to sport. Patient needs realistic expectations that recovery will be prolonged (12+ months), power may not fully recover, and complications are more likely. Follow-up includes monitoring renal function (anesthesia and surgery stress transplant), wound healing (immunosuppression increases infection risk), and gradual steroid weaning if transplant team agrees (to improve long-term tendon health).
KEY CLINICAL POINTS
Bilateral patellar tendon rupture is rare (less than 5%) and indicates systemic disease: steroids (most common), chronic renal disease + hyperparathyroidism, diabetes, rheumatoid arthritis, lupus, quinolone antibiotics; This patient has multiple risk factors (steroids, CKD, hyperparathyroidism, obesity); Spontaneous/low-energy mechanism with bilateral involvement = systemic pathology, NOT trauma
Staged vs simultaneous bilateral repair decision: Staged repair (2-3 week interval) preferred in most cases - allows patient to mobilize on un-operated leg between surgeries, reduces stiffness risk, safer in high-risk patients; Simultaneous repair only if young, fit, highly motivated with excellent social support; Bilateral repair has very difficult post-op rehabilitation (wheelchair-bound, bilateral non-weight-bearing, high DVT risk, 15-20% stiffness rate)
Multidisciplinary management essential: Involve nephrologist and transplant team to optimize medical management perioperatively; Cannot abruptly stop steroids (transplant rejection risk) but consider tapering long-term; Address secondary hyperparathyroidism if severe; Immunosuppression increases infection risk - meticulous wound care; Obesity increases anesthetic risk and mechanical stress on repairs; Blood tests: renal function, PTH, calcium, phosphate, vitamin D, HbA1c
Surgical technique modifications for poor tissue quality: Steroid-induced tendon degeneration results in worse tissue quality (mop-end tears, friable); MANDATORY augmentation with cerclage wire or suture tape to protect repair (even more important than standard case); Consider local tissue augmentation (quadriceps tendon turn-down flaps) if needed; Meticulous restoration of patella height (degenerate tissue easier to overtighten); Secure fixation with Krackow configuration and multiple sutures/anchors
Worse prognosis than standard unilateral rupture: Steroid use and renal disease impair healing; Re-rupture risk 10-15% (vs 5% in healthy patients); Permanent extensor lag more likely 20-30% (vs 10-20%); Recovery prolonged (12+ months); Goal is functional independence, not return to sport; Complications more frequent (infection from immunosuppression, stiffness from obesity and bilateral injury, DVT from immobility)
COMMON PITFALLS
Attempting simultaneous bilateral repair without considering post-op rehabilitation difficulties: Patient with bilateral repairs cannot weight-bear on either leg, wheelchair-bound for 6 weeks, very high dependency, major DVT/PE risk, deconditioning; Only attempt simultaneous if patient young, fit, motivated with excellent social support; For high-risk patient (obesity, renal disease), staged approach much safer
Not recognizing systemic etiology of bilateral rupture - missing opportunity to optimize medical management: Bilateral spontaneous rupture = systemic disease until proven otherwise; Must investigate and address steroid use, hyperparathyroidism, diabetes, inflammatory arthritis; Failing to involve nephrologist/transplant team risks perioperative complications (renal failure, transplant rejection, metabolic derangement); Patient needs long-term medical optimization (steroid weaning, PTH control) to prevent other tendon ruptures (Achilles, contralateral quad)
Overtightening degenerate tendon causing patella baja - easier mistake with poor tissue quality: Steroid-degenerate tendon is friable and stretches easily during tensioning; Surgeon may overtighten to 'feel secure' given poor tissue, but this creates patella baja (Insall-Salvati less than 0.8); Results in chronic anterior knee pain, patellofemoral wear, limited flexion - worse outcome than slight under-correction; Must use intraoperative lateral X-ray to confirm proper patellar height restoration (compare to contralateral side)
Not using augmentation in steroid-degenerate tissue - very high re-rupture risk: Steroids impair collagen synthesis and healing - repair without augmentation will fail in 15-20%; Cerclage wire or suture tape augmentation is MANDATORY, not optional, in steroid-related ruptures; Augmentation protects repair during healing phase and allows earlier safe mobilization; Not augmenting is accepting high re-rupture risk and condemning patient to likely failure
Underestimating infection risk from immunosuppression - meticulous wound care essential: Patient on tacrolimus and steroids has impaired immune response and wound healing; Surgical site infection rate 10-15% vs 2-5% in immunocompetent patients; Must use meticulous sterile technique, consider antibiotic-impregnated sutures, close wounds in layers carefully, avoid tension; Post-op wound monitoring crucial - any signs of infection (erythema, drainage) need aggressive treatment (IV antibiotics, possible debridement); Immunosuppressed patient with surgical infection can deteriorate rapidly
FURTHER QUESTIONS
"What systemic risk factors predispose to patellar tendon rupture?"
"If you stage the repairs, which knee would you repair first and why?"
"How does chronic steroid use affect tendon healing and what can be done to optimize healing?"
"What are the specific challenges of post-operative rehabilitation after bilateral patellar tendon repair?"
"Would you recommend reducing the steroid dose perioperatively in this renal transplant patient?"
CLINICAL SCENARIOCritical
Scenario 3: Chronic Neglected Patellar Tendon Rupture - Complex Reconstruction
CLINICAL PROMPT
"You are seeing a 38-year-old manual laborer in your clinic who was referred from a rural area. He sustained a patellar tendon rupture 9 months ago when he fell from a ladder at work. He was initially seen at a local hospital where he was told he had a 'knee sprain' and was given a knee brace and told to rest. He never had surgery. Over the past 9 months, he has been unable to work and has severe difficulty with stairs and standing from a seated position. He walks with a significant limp and cannot perform a straight leg raise. On examination, you note significant quadriceps atrophy, patella alta (the patella is palpable very high in the suprapatellar region), a large gap below the patella, and he has developed a significant extensor lag - he can achieve about 20° of active extension but cannot fully extend or hold the leg straight. His passive range of motion is 20° to 110° (he has developed a fixed flexion contracture). X-rays show an Insall-Salvati ratio of 2.1 indicating severe patella alta. The patellar tendon stump is retracted and scarred to the fat pad on MRI, and there is significant quadriceps muscle contracture and fatty infiltration. He is desperate to return to work and wants surgical reconstruction. How do you counsel him and what are the surgical options?"
PRACTICAL APPROACH
This is a chronic neglected patellar tendon rupture presenting at 9 months post-injury, which represents a significant reconstructive challenge. The patient has developed the classic triad of chronic neglected patellar tendon rupture: (1) severe patella alta (Insall-Salvati 2.1, normal less than 1.2, indicating massive proximal migration of patella), (2) tendon retraction and scarring (tendon stump adherent to fat pad, gap filled with scar tissue), and (3) quadriceps contracture with muscle degeneration (fatty infiltration on MRI, fixed flexion contracture 20°, cannot fully extend). These chronic changes make simple primary repair impossible - the tendon ends cannot be brought together due to retraction (gap is now 6-8cm+), and even if they could be approximated, the tension would be massive causing either immediate re-rupture or severe patella baja. Additionally, the quadriceps muscle has shortened and degenerated over 9 months, and forcibly lengthening it risks vascular compromise and further muscle damage. Counseling and realistic expectations: I need to have a frank discussion with this patient. This is a salvage situation, not a straightforward repair. The missed diagnosis and delayed presentation have resulted in chronic changes that significantly compromise potential outcomes. Surgical reconstruction is technically possible but has uncertain results - published series show 50-70% achieve functional extensor mechanism recovery (ability to walk, stairs, stand from chair) but only 30-40% achieve full active extension, and 20-30% have persistent extensor lag of 10-20° even after reconstruction. Return to manual labor is uncertain and may not be achievable. The alternative is to accept the extensor lag and manage with knee-ankle-foot orthosis (KAFO) or other bracing to stabilize the knee in extension for ambulation, but this is very limiting functionally and he would likely be unable to work. Given his age (38) and desire to work, I would recommend attempting surgical reconstruction despite the challenges, but he must understand the significant risks and uncertain outcomes. Surgical options for chronic neglected rupture: (1) V-Y Quadriceps Turndown (V-Y Lengthening): If there is some residual patellar tendon tissue and the gap is moderate (4-6cm), can perform V-Y advancement of the quadriceps tendon to gain length and reach the tibial tubercle. Technique: create a V-shaped incision in the quadriceps tendon proximally with apex superior, dissect the quadriceps free from the femur proximally to allow distal advancement, advance the flap distally (V becomes Y), repair any residual patellar tendon stump to tibial tubercle, close the quadriceps defect. Limited by available advancement (usually 4-6cm maximum) and creates a quadriceps defect that weakens extension. (2) Hamstring Autograft Reconstruction: Harvest ipsilateral semitendinosus and gracilis tendons, weave them through drill holes in the patella (transosseous tunnels) and tibial tubercle to create a neo-patellar tendon. Technique: drill multiple vertical tunnels in patella and tibial tubercle, weave hamstring grafts in figure-of-8 pattern through patella and tubercle to span the gap, augment with cerclage wire for protection. Advantage: autograft, no donor site issues, good for moderate gaps. Disadvantage: hamstring grafts are relatively thin and may stretch over time, creating two-tendon graft (4 strands) provides reasonable strength but inferior to native tendon. (3) Achilles Tendon Allograft Reconstruction: This is my preferred option for large gaps (greater than 6cm) and chronic cases. Use fresh-frozen Achilles tendon allograft with attached calcaneal bone block. Technique: prepare tibial tubercle with trough or tunnel to accept calcaneus bone block, fix bone block to tubercle with interference screw or screws providing bone-to-bone healing, weave the Achilles tendon portion through transosseous tunnels in the patella proximally, tension appropriately to restore patellar height (Insall-Salvati ~1.0), augment with cerclage wire/suture tape passed from tibial tubercle around patella or through quadriceps tendon. Advantages: spans large gaps, bone-to-bone healing at distal end is reliable, Achilles is thick strong tendon, single-stage. Disadvantages: allograft (disease transmission risk minimal but real, cost, availability), potential for graft incorporation failure (10-15%), technically demanding. (4) Contralateral Bone-Patellar Tendon-Bone (BTB) Autograft: Harvest central third of contralateral patellar tendon with bone blocks, use as interposition graft with bone blocks fixed to patella and tibial tubercle. Advantage: autograft avoids disease transmission, bone blocks allow secure fixation. Disadvantage: creates risk to healthy knee (donor site morbidity, potential weakening of contralateral extensor mechanism, patient psychologically averse to 'injuring' good knee), limited graft length. My recommendation for this patient: Given the 9-month delay, severe patella alta (Insall-Salvati 2.1), large gap, and quadriceps contracture with fatty infiltration, I would recommend Achilles tendon allograft reconstruction as it offers the best chance of spanning the gap and achieving functional reconstruction. Surgical technique in detail: (1) Midline incision, extensive exposure of retracted patellar tendon stump, patella, quadriceps, and tibial tubercle. (2) Mobilize patella and quadriceps distally - this requires careful dissection of adhesions in the suprapatellar region, release of quadriceps from femur proximally to allow distal advancement (quadriceps recession), may need lateral retinacular release. Caution: aggressive mobilization risks neurovascular compromise to quadriceps. (3) Prepare tibial tubercle with trough or tunnel to accept calcaneal bone block of Achilles allograft. (4) Fix calcaneus bone block into tibial tubercle with interference screw (7-9mm), ensuring secure bone-to-bone contact and compression. (5) Route Achilles allograft proximally through transosseous tunnels drilled vertically in patella (3 tunnels, 2.5mm drill), weave tendon through tunnels in locking configuration. (6) Tension the graft to restore patellar height - use intraoperative lateral C-arm X-ray to achieve Insall-Salvati ratio ~1.0 (slightly under-correct to account for graft stretching over time). This requires significant tension and judgment - too tight creates patella baja, too loose leaves persistent alta and extensor lag. (7) Augmentation: MANDATORY - pass cerclage wire (18-gauge) or heavy suture tape through tibial tubercle tunnel and around patella or through quadriceps tendon proximally, creating tension band to protect the allograft during healing and early motion. Without augmentation, graft will fail. (8) Close retinacular tears, ensure no patellar maltracking. Post-operative rehabilitation for chronic reconstruction: This is even more cautious than acute repair. Hinged knee brace locked in extension for 6-8 weeks, non-weight-bearing or touch-toe weight-bearing for 6-8 weeks to protect bone block healing and graft incorporation, passive ROM starting at 0-30° for first 4 weeks (very limited to prevent graft stretching), progressive flexion advancement 10-15° every 2 weeks (by 12 weeks aim for 90°), active quadriceps strengthening delayed until 8-12 weeks (isometrics first, then progressive resistance), full weight-bearing by 8-12 weeks, return to work at 6-12 months if achievable, aggressive physiotherapy to regain quad strength and address atrophy. Serial X-rays to monitor patellar height and check for graft stretching. Complications and prognosis: High complication rate in chronic reconstructions (30-40%) including re-rupture (10-15%), graft failure or stretching (persistent extensor lag 10-20°), stiffness (limited flexion due to cautious rehab and intra-articular adhesions from chronic injury), patella baja if overtightened, infection (2-5%), quadriceps weakness (permanent weakness 20-30% is common due to 9 months of atrophy and fatty infiltration). Functional outcomes: 50-70% achieve functional extensor mechanism (can walk, stairs, stand from chair, perform ADLs), 30-40% achieve full active extension (many have 10-20° extensor lag), 60-70% return to work in some capacity (may need modified duties, not full manual labor), patient satisfaction is mixed - many grateful to regain function after 9 months of disability, but disappointed by residual weakness and lag compared to normal. Prognosis worse than acute repair due to chronic muscle changes. Follow-up and work capacity: Patient will need ongoing physiotherapy for 12+ months, likely permanent restriction from heavy manual labor (lifting, climbing, kneeling), may be able to return to modified light duties, may need vocational rehabilitation to retrain for different work if manual labor not achievable, workers compensation claim is relevant (injury at work, missed diagnosis may be negligence by initial treating hospital - patient may pursue legal action for delayed diagnosis). Counsel that reconstruction is worthwhile attempt but outcomes uncertain, and even with successful surgery, he may not regain full pre-injury work capacity.
KEY CLINICAL POINTS
Chronic neglected patellar tendon rupture (9 months) is reconstructive challenge: Classic triad: (1) severe patella alta (Insall-Salvati 2.1), (2) tendon retraction and scarring (gap 6-8cm+, stump adherent to fat pad), (3) quadriceps contracture and degeneration (fatty infiltration, fixed flexion contracture 20°); Cannot perform simple primary repair - gap too large, tension would be massive causing re-rupture or patella baja, quadriceps shortened and degenerate; Requires complex reconstruction with autograft or allograft
Achilles tendon allograft reconstruction preferred for large gap chronic cases: Fresh-frozen Achilles allograft with calcaneus bone block spans gap 6-8cm+; Technique: fix calcaneus to tibial tubercle with interference screw (bone-to-bone healing), weave Achilles through transosseous tunnels in patella, restore height (Insall-Salvati ~1.0), augment with cerclage wire/tape; Advantages: reliable bone healing distally, strong thick tendon, single-stage; Disadvantages: allograft risks (disease transmission minimal, cost, availability), graft incorporation failure 10-15%; Alternative options: V-Y quadriceps lengthening (limited advancement 4-6cm), hamstring autograft (weaker, may stretch), contralateral BTB autograft (donor site morbidity to good knee)
Surgical technique requires quadriceps mobilization and precise tensioning: Must mobilize patella distally by releasing adhesions, quadriceps recession (release from femur proximally), may need lateral release; Caution: aggressive mobilization risks neurovascular compromise; Fix calcaneus bone block to tibial tubercle (interference screw, bone-to-bone healing); Tension allograft to restore patellar height (Insall-Salvati ~1.0, slight under-correction for graft stretch over time) - use intraoperative C-arm; Balance: too tight = patella baja, too loose = persistent alta and extensor lag; MANDATORY augmentation (cerclage wire/tape) to protect reconstruction
Post-operative rehabilitation is prolonged and cautious: Brace locked in extension 6-8 weeks, NWB/TTWB 6-8 weeks (bone block healing), passive ROM very limited initially (0-30° for 4 weeks to prevent graft stretch), progressive flexion 10-15° every 2 weeks (90° by 12 weeks), active quad strengthening delayed 8-12 weeks, full weight-bearing 8-12 weeks, return to work 6-12 months if achievable; Serial X-rays monitor patellar height and graft stretching; Much more cautious than acute repair due to chronic changes and reconstruction complexity
Prognosis significantly worse than acute repair - manage expectations: Functional outcomes: 50-70% achieve functional extensor mechanism (walk, stairs, ADLs), 30-40% achieve full active extension (many have 10-20° extensor lag), permanent quad weakness 20-30% (due to 9 months atrophy and fatty infiltration), return to manual labor uncertain (60-70% return to modified work, may not tolerate heavy labor); Complications: high rate 30-40% (re-rupture 10-15%, graft failure/stretching, stiffness, infection 2-5%, patella baja); Patient satisfaction mixed - grateful for function after disability but disappointed by residual weakness vs normal; Must counsel realistic expectations: reconstruction is salvage attempt, not restoration to normal
COMMON PITFALLS
Attempting simple primary repair in chronic case - guaranteed failure: After 9 months, tendon ends retracted 6-8cm apart and scarred, quadriceps contracted and degenerate; Trying to approximate ends with simple repair creates massive tension - will either re-rupture immediately or cause severe patella baja (Insall-Salvati less than 0.6); Quadriceps cannot be forcibly lengthened without risking vascular compromise and muscle necrosis; Must recognize this requires reconstruction (allograft or autograft interposition), not repair; Attempting repair without bridging gap is surgical error that wastes operative time and condemns patient to failure
Overtensioning the allograft creating patella baja - common error in chronic reconstruction: Surgeon wants to 'eliminate extensor lag' by tensioning graft very tight during fixation; Excessive tension pulls patella too far distally, creating patella baja (Insall-Salvati less than 0.8); Results in chronic anterior knee pain, patellofemoral arthritis, limited flexion (patella jammed into trochlea), worse outcome than slight under-correction; Must use intraoperative C-arm lateral X-ray to confirm Insall-Salvati ~1.0, slight under-correction acceptable (graft will stretch 5-10% over time); Better to accept 10° extensor lag than create patella baja
Not using augmentation in chronic reconstruction - very high graft failure risk: Chronic case has degenerate tissue, large gap, compromised biology (fatty infiltration, scarring); Allograft alone will stretch or fail in 20-30% without augmentation protection; Cerclage wire or heavy suture tape augmentation from tibial tubercle to patella/quadriceps is MANDATORY; Augmentation offloads graft during healing (first 12 weeks) and allows safer early motion; Not augmenting chronic reconstruction is accepting high failure rate and poor outcomes
Unrealistic expectations about return to manual labor - setting patient up for disappointment: Patient desperate to return to work after 9 months disability, surgeon wants to help; However, 9 months of quadriceps atrophy and fatty infiltration causes permanent muscle damage that won't fully recover even with successful reconstruction; Only 60-70% return to work in some capacity, many need modified light duties, heavy manual labor (lifting, climbing, kneeling) often not achievable; Must counsel realistic expectations: goal is functional independence (walk, stairs, ADLs), not return to pre-injury heavy labor; Overselling reconstruction ('you'll be back to work in 6 months lifting heavy loads') leads to disappointed patient and potential litigation when realistic outcomes (persistent weakness, possible extensor lag) are achieved
Not addressing workers compensation and missed diagnosis issues - patient may have legal case: Injury occurred at work (fall from ladder), initial hospital misdiagnosed as 'knee sprain' and missed patellar tendon rupture, 9-month delay has caused chronic changes requiring complex reconstruction with worse outcomes; Patient has potential workers compensation claim (injury at work, loss of income 9 months, possible permanent impairment); Also potential medical negligence claim against initial hospital (failure to diagnose, inappropriate conservative management); Surgeon must document thoroughly, inform patient of his rights, potentially coordinate with workers comp insurer/lawyer; Avoiding this discussion or minimizing the missed diagnosis is medicolegally risky and unfair to patient who has suffered from substandard initial care
FURTHER QUESTIONS
"What are the surgical options for chronic neglected patellar tendon rupture?"
"Why is Achilles tendon allograft preferred over hamstring autograft for large gaps?"
"How do you restore patellar height during reconstruction and what ratio are you targeting?"
"What is the functional prognosis after chronic patellar tendon reconstruction?"
"How does 9 months of quadriceps atrophy and fatty infiltration affect recovery potential?"
Management Algorithm
Algorithm
Patellar Tendon Quick Reference
Clinical summary
Diagnostic Triad
- •1. Palpable Gap (Infra-patellar)
- •2. Loss of Active Extension
- •3. Patella Alta (X-ray)
Radiology
- •Insall-Salvati: T/P
- •Normal: 1.0 (0.8-1.2)
- •Greater than 1.2 = Alta (Tendon Rupture)
- •Less than 0.8 = Baja (Quad Rupture)