This is a **missed Monteggia fracture** that has resulted in **chronic radial head dislocation** - one of the most significant medico-legal complications in orthopedic trauma. The initial injury was a Monteggia fracture-dislocation (ulna fracture with radial head dislocation), but the radial head dislocation was **not identified** at the time, likely because the radiocapitellar line was not checked on the lateral elbow X-ray. The ulna fracture was treated conservatively in a cast, and the fracture healed, but in a malunited position with anterior angulation. The radial head remained dislocated, and over 8 months has developed **chronic changes** that make treatment extremely challenging. **Why Monteggia injuries are commonly missed**: Up to **50% are missed initially**, especially in children. Common reasons: (1) **Radiocapitellar line not checked** - the key diagnostic line that must be drawn on every lateral elbow X-ray. (2) **Subtle dislocation** - on AP view radial head may appear nearly normal. (3) **Focus on obvious ulna fracture** - examiner fixates on the ulna and doesn't assess the radial head carefully. (4) **Inadequate imaging** - only forearm X-rayed without dedicated elbow views. **Pathological changes in chronic dislocation** (this case at 8 months): **Radial head changes**: Elongation and deformity from abnormal loading and growth disturbance (in children). **Capitellar changes**: Flattening and dome-shaped deformity from chronic pressure and lack of normal articulation (seen here). **Annular ligament**: Contracted, scarred, and unable to contain radial head. **Soft tissue contractures**: Capsular contractures limiting motion. **Ulna malunion**: Healed with residual angulation, shortened, contributing to radial head instability. These chronic changes make simple reduction impossible - the radial head will not stay reduced even if you could reduce it. **Management approach - extremely difficult problem**: The management of chronic Monteggia dislocation in children depends on **timing** (less than 3 months vs 3-12 months vs greater than 12 months) and **age** (younger children have better remodeling potential). This patient at 8 months is in the difficult middle zone. **Option 1: Attempted reconstruction** (generally reserved for less than 12 months duration and younger children): **Step 1: Ulna osteotomy** at the original fracture site to correct the malunion. Restore ulna length and alignment (anterior angulation must be corrected to allow radial head reduction). Fix with plate. This addresses the **primary deformity**. **Step 2: Open reduction of radial head** via lateral approach. Excise scar tissue. Attempt to reduce radial head into radiocapitellar joint. This is often difficult or impossible due to chronic soft tissue changes and bony deformity. **Step 3: Annular ligament reconstruction**: The native annular ligament is invariably scarred and inadequate. Reconstruct using **tendon graft** (palmaris longus, fascia lata, or triceps fascia). Loop the graft around the radial neck and secure to the ulna to contain the radial head. The **Bell Tawse technique** is commonly used. **Step 4: Assess stability**: Take the elbow through full ROM. If radial head remains unstable despite reconstruction, may need temporary K-wire fixation across the radiocapitellar joint (remove at 6 weeks). **Post-operative**: Above-elbow cast in supination 6 weeks. Then ROM exercises with close monitoring for re-dislocation. **Expected outcome**: Even with meticulous reconstruction, outcomes are **guarded**. Only 50-70% achieve satisfactory results with reconstruction in the 3-12 month timeframe. Common residual problems: Loss of full extension, loss of full supination, elbow stiffness, radial head re-dislocation, pain. **Option 2: Observation** (if minimally symptomatic or delayed presentation greater than 12 months): Accept the chronic dislocation and manage conservatively. Many children adapt reasonably well, though they will have permanent limited motion (especially terminal extension and supination). This is preferable to failed reconstruction which may worsen outcomes. Can consider radial head excision in late adolescence/adulthood if very symptomatic, though this is not ideal in children (loss of proximal radius support for longitudinal load transmission). **What should have been done initially**: Careful review of X-rays checking the **radiocapitellar line on the lateral view**. Any **isolated ulna fracture with displacement is a Monteggia until proven otherwise** - dedicated elbow X-rays mandatory. If identified acutely, ORIF of ulna would have led to radial head reduction in 95% of cases (Ring JBJS 1998), with excellent outcomes. **Medico-legal implications**: Missed Monteggia is a **significant medico-legal problem**. This is a **preventable complication** with proper radiographic assessment. The initial hospital failed to identify the radial head dislocation. The family should be counseled that: (1) This was a missed diagnosis initially, (2) Reconstruction is difficult with guarded outcomes, (3) There may be permanent functional limitations. Documentation must be meticulous. Consider involving hospital legal/risk management. **Counseling this family**: Explain that the original injury was a Monteggia fracture-dislocation that was not fully recognized at the initial hospital. The radial head dislocation has now been present for 8 months with chronic changes to the radial head, capitellum, and soft tissues. Reconstruction is possible but difficult, with only 50-70% chance of satisfactory outcome and likely some permanent stiffness and motion loss. Alternative is observation if symptoms are mild. Discuss options, realistic expectations, and involve the family in shared decision-making.