Aims. Complete ruptures of the ulnar collateral ligament (UCL) of the thumb are a common injury, yet little is known about their current management in the UK. The objective of this study was to assess the way complete UCL ruptures are managed in the UK. Methods. We carried out a multicentre, survey-based cross-sectional study in 37 UK centres over a 16-month period from June 2022 to September 2023. The survey results were analyzed descriptively. Results. A total of 37 centres participated, of which nine were tertiary referral hand centres and 28 were district general hospitals. There was a total of 112 respondents (69 surgeons and 43 hand therapists). The strongest influence on the decision to offer surgery was the lack of a firm ‘endpoint’ to stressing the metacarpophalangeal joint (MCPJ) in either full extension or with the MCPJ in 30° of flexion. There was variability in whether additional imaging was used in managing acute UCL injuries, with 46% routinely using additional imaging while 54% did not. The use of a bone anchor was by far the most common surgical option for reconstructing an acute ligament avulsion (97%, n = 67) with a transosseous suture used by 3% (n = 2). The most common duration of immobilization for those managed conservatively was six weeks (58%, n = 65) and four weeks (30%, n = 34). Most surgeons (87%, n = 60) and hand therapists (95%, n = 41) would consider randomizing patients with complete UCL ruptures in a future clinical trial. Conclusion. The management of complete UCL ruptures in the UK is highly variable in certain areas, and there is a willingness for clinical trials on this subject. Cite this article: Bone Jt Open 2024;5(8):708–714

Aims. We performed a systematic review of the current literature regarding the outcomes of unconstrained metacarpophalangeal joint (MCPJ) arthroplasty. Materials and Methods. We initially identified 1305 studies, and 406 were found to be duplicates. After exclusion criteria were applied, seven studies were included. Outcomes extracted included pre- and post-operative pain visual analogue scores, range of movement (ROM), strength of pinch and grip, satisfaction and patient reported outcome measures (PROMs). Clinical and radiological complications were recorded. The results are presented in three groups based on the design of the arthroplasty and the aetiology (pyrocarbon-osteoarthritis (pyro-OA), pyrocarbon-inflammatory arthritis (pyro-IA), metal-on-polyethylene (MoP)). Results. Results show that pyrocarbon implants provide an 85% reduction in pain, 144% increase of pinch grip and 13° improvements in ROM for both OA and IA combined. Patients receiving MoP arthroplasties had a reduction in pinch strength. Satisfaction rates were 91% and 92% for pyrocarbon-OA and pyrocarbon-IA groups, respectively. There were nine failures in 87 joints (10.3%) over a mean follow-up of 5.5 years (1.0 to 14.3) for pyro-OA. There were 18 failures in 149 joints (12.1%) over a mean period of 6.6 years (1.0 to 16.0) for pyro-IA. Meta-analysis was not possible due to the heterogeneity of the studies and the limited presentation of data. Conclusion. We would recommend prospective data collection for small joint arthroplasties of the hand consisting of PROMs that would allow clinicians to come to stronger conclusions about the impact on function of replacing the MCPJs. A national joint registry may be the best way to achieve this. Cite this article: Bone Joint J 2017;99-B:100–6

There are few reports describing dislocation of the metacarpophalangeal joint of the thumb in children. This study describes the clinical features and outcome of 37 such dislocations and correlates the radiological pattern with the type of dislocation. The mean age at injury was 7.3 years (3 to 13). A total of 33 children underwent closed reduction (11 under general anaesthesia). Four needed open reduction in two of which there was soft-tissue interposition. All cases obtained a good result. There was no infection, recurrent dislocation or significant stiffness. So-called ‘simple complete’ dislocations that present with the classic radiological finding of the joint at 90° dorsal angulation may be ‘complex complete’ injuries and require open reduction

We reviewed the records and radiographs of 381 patients with rheumatoid arthritis who had undergone silastic metacarpophalangeal joint replacement during the past 17 years. The number of implants was 1336 in the course of 404 operations. Implant failure was defined as either revision or fracture of the implant as seen on radiography. At 17 years, the survivorship was 63%, although on radiographs two-thirds of the implants were seen to be broken. Factors which improved survival included soft-tissue balancing, crossed intrinsic transfer and realignment of the wrist. Surgery to the thumb and proximal interphalangeal joint had a deleterious effect and the use of grommets did not protect the implant from fracture

We report the use of a free tendon graft in 70 patients to repair lesions of the capsuloligamentous complex of the metacarpophalangeal joint of the thumb. Of these 37 had a lesion of the ulnar collateral ligament, 18 of the radial collateral and 11 of the volar plate. Four patients had combined lesions. We outline our techniques and review 51 of the patients. Of those 47 (92%) were satisfied, and all but one had regained full stability. Pinch grip strength was normal in 48. About one-third of the patients had some loss of flexion/extension; this was seldom noticed by the patients and caused no significant disability. Free tendon graft reconstruction is indicated for severe fresh lesions, for old lesions with chronic disability and for lesions which have not responded to conservative management

Ten cases of complete rupture of the collateral ligaments of the metacarpophalangeal finger joints are reported. The nature of this injury, the pre-operative morbidity and the intra-operative pathology are analysed. In all cases surgery was performed with satisfactory results. Operation is indicated for joint stability, grip and pinch strength, pain control and early functional recovery.

Aims. The objective of this systematic review was to describe trapeziectomy outcomes and complications in the context of osteoarthritis of the base of the thumb after a five-year minimum follow-up. Methods. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to guide study design, and 267 full-text articles were assessed for eligibility. After exclusion criteria application, 22 studies were included, involving 728 patients and 823 trapeziectomies. Outcomes included pre- and postoperative clinical and radiological characteristics. Complications and revisions were recorded. Results. All the studies reported good results regarding pain and range of motion at the last follow-up of 8.3 years (5 to 22); the mean satisfaction rate was 91% (84% to 100%). It was difficult to assess the impact on metacarpophalangeal joint motion in extension with contrary results. The key pinch returned to its preoperative values, whereas tip pinch showed a modest improvement (+14%), with a mild improvement found in grip strength (+25%) at the last follow-up. The mean progressive trapezial collapse was 48% (0% to 85%) and was not correlated with pain, grip strength, or satisfaction. The most represented complications were linked to tendons or nerves affected during additional procedures to stabilize the joint (11.6%; n = 56). Mechanical complications included symptomatic scapho-M1 impingement (3.1%; n = 15/580), leading to nine surgical revisions out of 581 trapeziectomies. Meta-analysis was not possible due to study heterogeneity and limited data. Conclusion. After a minimum five-year follow-up, trapeziectomy achieved high patient satisfaction and pain relief. However, strength seemed to be deteriorating with detrimental consequences, but this did not correlate with trapezial collapse. The issues related to underestimating mechanical complications and varying degrees of success should be highlighted in the information given to patients. Evidence-based analyses should help the surgeon in their decision-making. Cite this article: Bone Jt Open 2021;2(3):141–149

Aims. The results of surgery for Dupuytren’s disease can be compromised by the potential for disease recurrence and loss of function. Selecting which patients will benefit from repeat surgery, when to operate, and what procedure to undertake requires judgement and an understanding of patient expectations and functional needs. We undertook this study to investigate patient outcomes and satisfaction following repeat limited fasciectomy for recurrent Dupuytren’s disease. Methods. We prospectively identified all patients presenting with recurrence of Dupuytren’s disease who were selected for surgical treatment with repeat limited fasciectomy surgery between January 2013 and February 2015. Patients were assessed preoperatively, and again at a minimum of five years postoperatively. We identified 43 patients who were carefully selected for repeat fasciectomy involving 54 fingers. Patients with severe or aggressive disease with extensive skin involvement were not included; in our practice, these patients are instead counselled and preferentially treated with dermofasciectomy. The primary outcome measured was change in the Michigan Hand Outcomes Questionnaire (MHQ) score. Secondary outcomes were change in finger range of motion, flexion contracture, Semmes-Weinstein monofilament (SWM) values, and overall satisfaction. Results. There was a significant improvement in MHQ scores, across all domains, with a mean overall score increase of 24 points (p < 0.001). The summed flexion contracture across the metacarpophalangeal joint (MCPJ) and the proximal interphalangeal joint (PIPJ) reduced from means of 72.0° (SD 15.9°) to 5.6° (SD 6.8°) (p < 0.001). A significant increase in maximal flexion was seen at the MCPJ (p < 0.001) but not the PIPJ (p = 0.550). The mean overall satisfaction score from the visual analogue scale was 8.9 (7.9 to 10.0). Complications were uncommon although five fingers showed reduced sensibility at final follow-up. Conclusion. Our study shows that repeat limited fasciectomy for selected patients presenting with recurrence of Dupuytren’s disease can be an effective and safe treatment resulting in excellent patient-reported outcomes and levels of satisfaction. Cite this article: Bone Joint J 2021;103-B(5):946–950

Aims. In the UK, fasciectomy for Dupuytren’s contracture is generally performed under general or regional anaesthetic, with an arm tourniquet and in a hospital setting. We have changed our practice to use local anaesthetic with adrenaline, no arm tourniquet, and perform the surgery in a community setting. We present the outcome of a consecutive series of 30 patients. Methods. Prospective data were collected for 30 patients undergoing open fasciectomy on 36 digits (six having two digits affected), over a one-year period and under the care of two surgeons. In total, 10 ml to 20 ml volume of 1% lidocaine with 1:100,000 adrenaline was used. A standard postoperative rehabilitation regime was used. Preoperative health scores, goniometer measurements of metacarpophalangeal (MCP), proximal interphalangeal (PIP) contractures, and Unité Rheumatologique des Affections de la Main (URAM) scores were measured pre- and postoperatively at six and 12 weeks. Results. The mean preoperative contractures were 35.3° (0° to 90°) at the metacarpophalangeal joint (MCPJ), 32.5° (0° to 90°) at proximal interphalangeal joint (PIPJ) (a combined deformity of 67.8°). The mean correction was 33.6° (0° to 90°) for the MCPJ and 18.2° (0° to 70°) for the PIPJ leading to a combined correction of 51.8°. There was a complete deformity correction in 21 fingers (59.5%) and partial correction in 14 digits (37.8%) with no correction in one finger. The mean residual deformities for the partial/uncorrected group were MCP 4.2° (0° to 30°), and PIP 26.1° (0° to 85°). For those achieving a full correction the mean preoperative contracture was less particularly at the PIP joint (15.45° (0° to 60°) vs 55.33° (0° to 90°)). Mean preoperative URAM scores were higher in the fully corrected group (17.4 (4 to 31) vs 14.0 (0 to 28)), but lower at three months post-surgery (0.5 (0 to 3) vs 4.40 (0 to 18)), with both groups showing improvements. Infections occurred in two patients (three digits) and both were successfully treated with oral antibiotics. No other complications were noted. The estimated cost of a fasciectomy under local anaesthetic in the community was £184.82 per patient. The estimated hospital theatre costs for a fasciectomy was £1,146.62 under general anaesthetic (GA), and £1,085.30 under an axillary block. Conclusion. This study suggests that a fasciectomy performed under local anaesthetic with adrenaline and without an arm tourniquet and in a community setting is safe, and results in favourable outcomes regarding the degree of correction of contracture achieved, functional scores, and short-term complications. Local anaesthetic fasciectomy in a community setting achieves a saving of £961.80 for a GA and £900.48 for an axillary block per case. Cite this article: Bone Joint J 2020;102-B(10):1354–1358

The April 2023 Wrist & Hand Roundup³⁶⁰ looks at: MRI-based classification for acute scaphoid injuries: the OxSMART; Deep learning for detection of scaphoid fractures?; Ulnar shortening osteotomy in adolescents; Cost-utility analysis of thumb carpometacarpal resection arthroplasty; Arthritis of the wrist following scaphoid fracture nonunion; Extensor hood injuries in elite boxers; Risk factors for reoperation after flexor tendon repair; Nonoperative versus operative treatment for displaced finger metacarpal shaft fractures.

Aims

This study aims to report the outcomes in the treatment of unstable proximal third scaphoid nonunions with arthroscopic curettage, non-vascularized bone grafting, and percutaneous fixation.

Aims

The aim of this study was to assess and compare active rotation of the forearm in normal subjects after the application of a short-arm cast (SAC) in the semisupination position and a long-arm cast (LAC) in the neutral position. A clinical study was also conducted to compare the functional outcomes of using a SAC in the semisupination position with those of using a LAC in the neutral position in patients who underwent arthroscopic triangular fibrocartilage complex (TFCC) foveal repair.

We used high-resolution ultrasonography to image the ulnar collateral ligament in 39 patients who had sustained recent injuries of the metacarpophalangeal joint of the thumb. All the patients were subsequently operated on and the lesions of the ligament were recorded. In 36 patients the preoperative ultrasonographic diagnosis was correct. Five of these showed no rupture of the ligament. In the other 31, ultrasonography correctly distinguished between rupture in situ (15) and rupture with dislocation of the ligament (16). Misdiagnosis by ultrasonography in three cases was due to delay of the investigation (three weeks after injury) in one, to technical error in one and to misinterpretation of the image in one

We randomly selected 39 patients undergoing excision of the trapezium for osteoarthritis of the first carpometacarpal joint into two groups, with mobilisation either at one or at four weeks after operation. The patients were reviewed at a median of six months (6 to 8). The clinical details, the severity of the disease and the preoperative clinical measurements of both groups were similar. Excision of the trapezium resulted in significant improvement in objective and subjective function. Comparison of the outcomes of the two groups showed no differences except that patients found early mobilisation significantly more convenient. Although there was no significant difference in the range of movement between the groups, there was a small loss of movement at the metacarpophalangeal joint in the late mobilisation group. Our findings show that simple excision of the trapezium is an effective procedure for patients with carpometacarpal osteoarthritis of the thumb and that prolonged splintage is neither necessary nor desirable

Various prostheses for total replacement of the first metatarsophalangeal joint for painful hallux valgus and hallux rigidus are briefly discussed. Altogether, the results of eighty-six replacements in sixty-nine patients have been recorded after an average interval of two years. In seventy-eight operations a Silastic* prosthesis as designed by Swanson for the replacement of metacarpophalangeal joints was used, with no case of fracture or deep infection up to date. Overall, the assessment of pain showed that 98 per cent of operations gave either complete or considerable relief. For hallux valgus, the objective assessment showed excellent or good results in 79 per cent, fair in 16 per cent and poor in 5 per cent. For hallux rigidus the corresponding figures were 86, 14 and 0. The technique of replacement described promises to be most satisfactory, especially for hallux rigidus. In selected cases of hallux valgus, a basal osteotomy of the first metatarsal should be added

1. A new procedure, called "the extensor diversion graft operation", has been devised for correcting the deformity and reducing the disability of the intrinsic minus fingers so commonly seen in leprosy. 2. The procedure consists of the insertion of a free tendon graft which spans the metacarpophalangeal joint along its volar aspect and is attached at both ends to the extensor mechanism, to the extensor tendon proximally and to the lateral band distally. 3. The procedure reduces extensor dominance at the metacarpo-phalangeal joint and improves the balance of forces, allowing the assumption of a straight posture by use of the extrinsic muscles. 4. The assessment of function of ninety-seven fingers on average eight months after operation has shown that in addition to correction of deformity, this procedure in the majority of cases also restores partial independence of movement at the metacarpo-phalangeal and proximal interphalangeal joints, to such an extent that the finger can reach and hold a functionally useful position. 5. One advantage of the procedure is that it obviates the need for re-education of muscles

Aims

This exploratory randomized controlled trial (RCT) aimed to determine the splint-related outcomes when using the novel biodegradable wood-composite splint (Woodcast) compared to standard synthetic fibreglass (Dynacast) for the immobilization of undisplaced upper limb fractures in children.

Aims

Torus fractures are the most common childhood fracture, accounting for 500,000 UK emergency attendances per year. UK treatment varies widely due to lack of scientific evidence. This is the protocol for a randomized controlled equivalence trial of ‘the offer of a soft bandage and immediate discharge’ versus ‘rigid immobilization and follow-up as per the protocol of the treating centre’ in the treatment of torus fractures .

Objectives

Staphylococcus aureus (S. aureus) is the most commonly implicated organism in septic arthritis, a condition that may be highly destructive to articular cartilage. Previous studies investigating laboratory and clinical strains of S. aureus have demonstrated that potent toxins induced significant chondrocyte death, although the precise toxin or toxins that were involved was unknown. In this study, we used isogenic S. aureus mutants to assess the influence of alpha (Hla)-, beta (Hlb)-, and gamma (Hlg)-haemolysins, toxins considered important for the destruction of host tissue, on in situ bovine chondrocyte viability.

Abstract

Nerve transfer has become a common and often effective reconstructive strategy for proximal and complex peripheral nerve injuries of the upper limb. This case-based discussion explores the principles and potential benefits of nerve transfer surgery and offers in-depth discussion of several established and valuable techniques including: motor transfer for elbow flexion after musculocutaneous nerve injury, deltoid reanimation for axillary nerve palsy, intrinsic re-innervation following proximal ulnar nerve repair, and critical sensory recovery despite non-reconstructable median nerve lesions.

Objectives

Little is known about tissue changes underlying bone marrow lesions (BMLs) in non-weight-bearing joints with osteoarthritis (OA). Our aim was to characterize BMLs in OA of the hand using dynamic histomorphometry. We therefore quantified bone turnover and angiogenesis in subchondral bone at the base of the thumb, and compared the findings with control bone from hip OA.

Aims

Outcome measures quantifying aspects of health in a precise, efficient, and user-friendly manner are in demand. Computer adaptive tests (CATs) may overcome the limitations of established fixed scales and be more adept at measuring outcomes in trauma. The primary objective of this review was to gain a comprehensive understanding of the psychometric properties of CATs compared with fixed-length scales in the assessment of outcome in patients who have suffered trauma of the upper limb. Study designs, outcome measures and methodological quality are defined, along with trends in investigation.

Bone loss involving articular surface is a challenging problem faced by the orthopaedic surgeon. In the hand and wrist, there are articular defects that are amenable to autograft reconstruction when primary fixation is not possible. In this article, the surgical techniques and clinical outcomes of articular reconstructions in the hand and wrist using non-vascularised osteochondral autografts are reviewed.

The February 2014 Wrist & Hand Roundup³⁶⁰ looks at: simple debridement and ulnar-sided wrist pain; needle fasciotomy or collagenase injection; joint replacement in osteoarthritic knuckles; the Mannerfelt arthrodesis; scaphoid union rates with conservative treatment; the benefits of atorvastatin for muscle re-innervation after sciatic nerve transection; and complications of trapeziectomy.

Aims

The aim of this study was to compare the Push Ortho Thumb Brace CMC and a custom-made orthosis in the treatment of patients with primary osteoarthritis of the carpometacarpal joint of the thumb. Our outcome measures were pain scores, tests of hand function, patient satisfaction and patient preference.

We retrospectively compared wrist arthrodesis using the Mannerfelt technique in 19 or an AO-plate in 23 patients with long-standing rheumatoid arthritis. The mean follow-up was for 76 months.

Compared with the Mannerfelt fusion group, patients in the AO-plate group reported greater satisfaction with their wrist function (74% vs 37%, p = 0.015). Complications were reported in six wrists in the AO-plate group and two wrists in the Mannerfelt fusion group (p = 0.258). At final follow-up, 95% of patients (41) reported either no pain or only mild pain. There was improvement in flexion of the finger joints in both groups but no significant improvement in the extension lag in either group.

Both methods relieve pain and improve function. Overall, the activities of daily living scores and the patients’ subjective assessment of outcome tended to be higher in the AO-plate group than in the Mannerfelt fusion group, although the difference was not statistically significant. Similarly, although more postoperative complications occurred in the AO-plate group, the difference between the two groups was not statistically significant.

We report a new surgical technique for the treatment of traumatic dislocation of the carpometacarpal (CMC) joint of the thumb. This is a tenodesis which uses part of the flexor carpi radialis.

Between January 2010 and August 2013, 13 patients with traumatic instability of the CMC joint of the thumb were treated using this technique. The mean time interval between injury and ligament reconstruction was 13 days (0 to 42). The mean age of the patients at surgery was 38 years: all were male.

At a mean final follow-up of 26 months (24 to 29), no patient experienced any residual instability. The mean total palmar abduction of the CMC joint of the thumb was 61° and the mean radial abduction 65° The mean measurements for the uninjured hand were 66° (60° to 73°) and 68° (60° to 75°), respectively. The mean Kapandji thumb opposition score was 8.5° (8° to 9°). The mean pinch and grip strengths of the hand were 6.7 kg (3.4 to 8.2) and 40 kg (25 to 49), respectively. The mean Disabilities of the Arm, Shoulder, and Hand questionnaire score was 3 (1 to 6). Based on the Smith and Cooney score, we obtained a mean score of 85 (75 to 95), which included four excellent, seven good, and two fair results.

Our technique offers an alternative method of treating traumatic dislocation of the CMC joint of the thumb: it produces a stable joint and acceptable hand function.

Cite this article: Bone Joint J 2015;97-B:1533–8.

Aims

Between 2002 and 2011, 81 patients with a traumatic total brachial plexus injury underwent reconstruction by double free muscle transfer (DFMT, 47 cases), single muscle transfer (SMT, 16 cases) or nerve transfers (NT, 18 cases).

The April 2015 Wrist & Hand Roundup360 looks at: Non-operative hand fracture management; From the sublime to the ridiculous?; A novel approach to carpal tunnel decompression; Osteoporosis and functional scores in the distal radius; Ulnar variance and force distribution; Tourniquets in carpal tunnel under the spotlight; Scaphoid fractures reclassified; Osteoporosis and distal radial fracture fixation; PROMISing results in the upper limb

We systematically reviewed all the evidence published in the English language on proximal interphalangeal joint (PIPJ) replacement, to determine its effectiveness on the function of the hand and the associated post-operative complications.

Original studies were selected if they reported clinical outcome with a minimum of one year’s follow-up. Quality was assessed using the Cowley systematic review criteria modified for finger-joint replacements. Of 319 articles identified, only five were adequately reported according to our quality criteria; there were no randomised controlled trials. PIPJ replacements had a substantial effect size on hand pain of -23.2 (95% confidence interval (CI) -27.3 to -19.1) and grip strength 1.2 (95% CI -10.7 to 13.1), and a small effect on range of movement 0.2 (95% CI -0.4 to 0.8). A dorsal approach was most successful. Post-operative loosening occurred in 10% (95% CI 3 to 30) of ceramic and 12.5% (95% CI 7 to 21) of pyrocarbon replacements. Post-operative complications occurred in 27.8% (95% CI 20 to 37).

We conclude that the effectiveness of PIPJ replacement has not been established. Small observational case studies and short-term follow-up, together with insufficient reporting of patient data, functional outcomes and complications, limit the value of current evidence.

We recommend that a defined core set of patients, surgical and outcome data for this intervention be routinely and systematically collected within the framework of a joint registry.

This paper describes the presence of tenodesis effects in normal physiology and explores the uses of operative tenodesis in surgery of the upper limb.

While primary squamous-cell carcinoma of the hand is common, metastasis of a squamous-cell carcinoma to the hand is very rare. It has been reported to arise from carcinoma of the lung and oesophagus and, rarely, from other tumours. We describe a patient with metastatic squamous-cell carcinoma occurring in the first web space of the hand from primary lung cancer, which remained undetected for 30 months after treatment of the metastasis.

We measured the tension in the interosseous membrane in six cadaveric forearms using an in vitro forearm testing system with the native radial head, after excision of the radial head and after metallic radial head replacement. The tension almost doubled after excision of the radial head during simulated rotation of the forearm (p = 0.007). There was no significant difference in tension in the interosseous membrane between the native and radial head replacement states (p = 0.09). Maximal tension occurred in neutral rotation with both the native and the replaced radial head, but in pronation if the radial head was excised. Under an increasing axial load and with the forearm in a fixed position, the rate of increase in tension in the interosseous membrane was greater when the radial head was excised than for the native radial head or replacement states (p = 0.02). As there was no difference in tension between the native and radial head replacement states, a radial head replacement should provide a normal healing environment for the interosseous membrane after injury or following its reconstruction. Load sharing between the radius and ulna becomes normal after radial head Replacement. As excision of the radial head significantly increased the tension in the interosseous membrane it may potentially lead to its attritional failure over time.

Cite this article: Bone Joint J 2013;95-B:1383–7.

The aim of this study was to determine whether subchondral bone influences in situ chondrocyte survival. Bovine explants were cultured in serum-free media over seven days with subchondral bone excised from articular cartilage (group A), subchondral bone left attached to articular cartilage (group B), and subchondral bone excised but co-cultured with articular cartilage (group C). Using confocal laser scanning microscopy, fluorescent probes and biochemical assays, in situ chondrocyte viability and relevant biophysical parameters (cartilage thickness, cell density, culture medium composition) were quantified over time (2.5 hours vs seven days). There was a significant increase in chondrocyte death over seven days, primarily within the superficial zone, for group A, but not for groups B or C (p < 0.05). There was no significant difference in cartilage thickness or cell density between groups A, B and C (p > 0.05). Increases in the protein content of the culture media for groups B and C, but not for group A, suggested that the release of soluble factors from subchondral bone may have influenced chondrocyte survival. In conclusion, subchondral bone significantly influenced chondrocyte survival in articular cartilage during explant culture.

The extrapolation of bone-cartilage interactions in vitro to the clinical situation must be made with caution, but the findings from these experiments suggest that future investigation into in vivo mechanisms of articular cartilage survival and degradation must consider the interactions of cartilage with subchondral bone.