Kienbock Disease — Surgical Management

Kienbock disease (avascular necrosis of the lunate) is managed surgically once conservative treatment has failed and symptoms are intrusive. Two independent variables govern every decision: the Lichtman radiographic stage (the degree of lunate collapse and carpal instability) and the ulnar variance (which determines which joint-levelling procedure is biomechanically appropriate).

Absolute indications for surgery - Lichtman stage IIA or greater with persistent pain despite 3-6 months of conservative treatment (immobilisation, NSAIDs, activity modification)

• Progressive lunate collapse on serial radiographs
• Loss of carpal height or fixed scaphoid flexion (stage IIIB)
• Pancarpal arthritis (stage IV) Relative indications - Stage I with persistent symptoms greater than 6 months despite immobilisation (some surgeons offer earlier joint levelling in manual labourers)
• Bilateral Kienbock disease (operate the more symptomatic side first)
• Patient preference for definitive surgical management over prolonged immobilisation

Conservative management first. Stage I and early stage IIA disease may be managed with a short-arm thumb spica cast or splint for 4-12 weeks to reduce mechanical load on the lunate, with activity modification and NSAIDs. Approximately 20-30 percent of stage I patients improve with immobilisation alone, though many progress to surgery. Core decompression (percutaneous drilling of the lunate to stimulate vascular channels) is a low-morbidity option for early stages (I-IIA) regardless of ulnar variance, with small case series reporting symptom improvement in 60-80 percent of patients. Consent specifically for: nonunion (1-5 percent after radial shortening, 5-10 percent after capitate shortening), progressive lunate collapse (10-20 percent despite an adequate joint-levelling procedure), DRUJ overload from excessive radial shortening, wrist stiffness, complex regional pain syndrome, and the possibility that the chosen procedure may not fully relieve symptoms (about 10-20 percent of patients ultimately require a salvage operation). Setup. Supine, arm abducted 90 degrees on a hand table with the forearm in neutral rotation (essential for confirming ulnar variance on fluoroscopy), upper-arm tourniquet inflated to 250 mmHg. General or regional (brachial plexus) anaesthesia depending on duration — regional suffices for an isolated osteotomy; combined procedures favour general anaesthesia. Prophylactic antibiotics (e.g. cefazolin 2 g IV at induction), as the procedure involves bone work and implants. Position the C-arm from the ulnar side to allow AP and lateral imaging without moving the arm.

The goal is to offload or replace the avascular lunate through the dorsal approach — the workhorse exposure for every procedure in Kienbock disease. The exposure is laid out in full as the first steps below (it is the heart of the operation); the procedure then diverges by stage and ulnar variance into joint levelling, salvage, or revascularisation.

View larger

After exposure, the procedure diverges. Joint-levelling osteotomies (radial or capitate shortening) are used in stages I-IIIA; at stage IIIB the algorithm shifts to motion-sparing salvage (STT/scaphocapitate fusion or PRC); stage IV requires total wrist fusion or arthroplasty; revascularisation is added for a viable lunate.

Rehabilitation | Phase | Timing | Focus | |-------|--------|-------| | Immediate | Day 0-7 | Elevation for 48 hours; interim splint or cast; paracetamol and NSAIDs (short opioid course 48-72 hours); finger flexion-extension from day 1 to prevent digital stiffness; wound check at 5-7 days | | Immobilisation | Weeks 1-6 | Procedure-specific cast/splint (see table); finger and elbow range of motion throughout | | Rehabilitation | Weeks 6-12 | Progressive wrist range of motion under hand therapy; avoid heavy loading for 8-12 weeks after osteotomy and 12-16 weeks after fusion; grip strengthening once bony healing is confirmed | | Return to function | Weeks 12-16+ | Office work at 2-4 weeks (osteotomy) or 6-8 weeks (fusion); manual work at 8-12 weeks (osteotomy/PRC) or 12-16 weeks (fusion); driving at 4-6 weeks (osteotomy/PRC) or 8-12 weeks (fusion) |

Complications

If joint levelling fails. Persistent or worsening pain more than 6 months after a united osteotomy, with progressive carpal height loss or lunate fragmentation, means the disease has progressed despite offloading (10-20 percent of cases — a property of the disease, not necessarily a technical error). Confirm osteotomy union on CT (to exclude nonunion as the cause of pain), assess the current Lichtman stage, and MRI the capitate head: if IIIA or early IIIB with intact capitate cartilage, move to STT fusion or PRC; if IIIB with capitate chondrosis or stage IV, proceed to total wrist fusion.

Epidemiology. Kienbock disease most often affects the dominant wrist of men aged 20-40 who perform manual labour. Bilateral involvement occurs in approximately 2-5 percent of patients, and is more common with systemic risk factors such as steroid use, sickle cell disease and systemic lupus erythematosus. Pathoanatomy — the lunate blood supply. The lunate receives blood through dorsal and volar vascular pedicles entering via its ligamentous attachments. This anatomy explains why the disease occurs and underpins revascularisation procedures. - Dorsal vessels (the primary supply in 70-80 percent of lunates): enter through the dorsal radiocarpal and intercarpal ligaments, arising from the radial artery via dorsal branches and the anterior interosseous artery, and supply about two-thirds to three-quarters of the bone. They are the most vulnerable to disruption in dorsal fracture patterns and surgical dissection.

• Volar vessels (supplemental): enter through the radiolunotriquetral and volar radiocarpal ligaments and supply the volar pole; in a minority of lunates they are the sole supply.
• Viegas (1999) vascular types: Type I — a single vessel (about 20 percent of lunates, the highest AVN risk); Type II — two vessels with dorsal dominance (about 60 percent); Type III — multiple dorsal and volar vessels (about 20 percent, the lowest risk). A Type I lunate is the most vulnerable to AVN after injury, and repetitive loading in an ulnar-negative wrist concentrates force on the radial side of the lunate, microfracturing trabeculae and disrupting the dorsal vessels. Why the operation works — DRUJ biomechanics. Ulnar variance (the relative length of the ulna and radius at the DRUJ) determines load distribution across the wrist. In an ulnar-negative wrist the ulna is shorter and a greater proportion of axial load falls on the lunate through the radius. Radial shortening corrects this by shortening the radius and equalising load between radius and ulna; excessive shortening reverses the imbalance, overloading the ulnar side of the DRUJ. The Lichtman classification (revised 2002, MRI-enhanced) remains the framework that drives management:

Key evidence. Radial shortening is the most studied procedure: Weiss et al. (1991) reported 94 percent good-to-excellent results in 36 wrists at an average 5-year follow-up, and a systematic review (Shin et al., 2018) found radial osteotomy superior to non-operative management for symptomatic disease. For neutral or positive variance, Bain et al. (2020) described a simplified single-cut single-screw capitate-shortening technique that offloads the lunate without disturbing the DRUJ. Vascularised bone grafting shows better radiographic revascularisation than non-operative care in early disease (Park et al., 2023), especially when combined with joint levelling. For salvage, PRC gives reliable long-term relief when the capitate cartilage is intact (Croog and Stern, 2008, average 10-year follow-up), and STT fusion preserves carpal height in stage IIIB (Minami et al., 2003). The modern reference (Lichtman and Pientka, 2025) integrates the osseous Lichtman stage with perfusion (Schmitt) and articular cartilage (Bain) classification systems.