Objectives

Osteochondral injuries, if not treated adequately, often lead to severe osteoarthritis. Possible treatment options include refixation of the fragment or replacement therapies such as Pridie drilling, microfracture or osteochondral grafts, all of which have certain disadvantages. Only refixation of the fragment can produce a smooth and resilient joint surface. The aim of this study was the evaluation of an ultrasound-activated bioresorbable pin for the refixation of osteochondral fragments under physiological conditions.

Trochlear dysplasia is a developmental condition characterised by an abnormally flat or dome-shaped trochlea and is an important contributory factor to patellofemoral instability and recurrent dislocation. We studied prospectively a series of 54 consecutive patients (59 knees) with patellofemoral instability secondary to trochlear dysplasia, who were treated by a trochleoplasty by a single surgeon between June 2002 and June 2007.

Pre- and post-operative scores were assessed by the patients and a satisfaction questionnaire was completed.

Of the 54 patients (59 knees) in the series, 39 (44 knees) were female and 15 (15 knees) were male. Their mean age at surgery was 21 years and 6 months (14 years 4 months to 33 years 11 months). In 40 patients (42 knees) the mean follow-up was for 24 months (12 to 58). One patient was unable to attend for follow-up. An analysis of the results of those patients followed up for at least 12 months showed a statistically significant improvement in outcome (p < 0.001 for all scores). Overall, 50 patients (92.6%) were satisfied with the outcome of their procedure.

The early results of trochleoplasty are encouraging in this challenging group of patients.

Gene therapy with insulin-like growth factor-1 (IGF-1) increases matrix production and enhances chondrocyte proliferation and survival in vitro. The purpose of this study was to determine whether arthroscopically-grafted chondrocytes genetically modified by an adenovirus vector encoding equine IGF-1 (AdIGF-1) would have a beneficial effect on cartilage healing in an equine femoropatellar joint model.

A total of 16 horses underwent arthroscopic repair of a single 15 mm cartilage defect in each femoropatellar joint. One joint received 2 × 10⁷ AdIGF-1 modified chondrocytes and the contralateral joint received 2 × 10⁷ naive (unmodified) chondrocytes. Repairs were analysed at four weeks, nine weeks and eight months after surgery. Morphological and histological appearance, IGF-1 and collagen type II gene expression (polymerase chain reaction, in situ hybridisation and immunohistochemistry), collagen type II content (cyanogen bromide and sodium dodecyl sulphate-polyacrylamide gel electrophoresis), proteoglycan content (dimethylmethylene blue assay), and gene expression for collagen type I, matrix metalloproteinase (MMP)-1, MMP-3, MMP-13, aggrecanase-1, tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and TIMP-3 were evaluated.

Genetic modification of chondrocytes significantly increased IGF-1 mRNA and ligand production in repair tissue for up to nine weeks following transplantation. The gross and histological appearance of IGF-1 modified repair tissue was improved over control defects. Gross filling of defects was significantly improved at four weeks, and a more hyaline-like tissue covered the lesions at eight months. Histological outcome at four and nine weeks post-transplantation revealed greater tissue filling of defects transplanted with genetically modified chondrocytes, whereas repair tissue in control defects was thin and irregular and more fibrous. Collagen type II expression in IGF-1 gene-transduced defects was increased 100-fold at four weeks and correlated with increased collagen type II immunoreaction up to eight months.

Genetic modification of chondrocytes with AdIGF-1 prior to transplantation improved early (four to nine weeks), and to a lesser degree long-term, cartilage healing in the equine model.

The equine model of cartilage healing closely resembles human clinical cartilage repair. The results of this study suggest that cartilage healing can be enhanced through genetic modification of chondrocytes prior to transplantation.

Cartilage defects of the hip cause significant pain and may lead to arthritic changes that necessitate hip replacement. We propose the use of fresh osteochondral allografts as an option for the treatment of such defects in young patients. Here we present the results of fresh osteochondral allografts for cartilage defects in 17 patients in a prospective study. The underlying diagnoses for the cartilage defects were osteochondritis dissecans in eight and avascular necrosis in six. Two had Legg-Calve-Perthes and one a femoral head fracture. Pre-operatively, an MRI was used to determine the size of the cartilage defect and the femoral head diameter. All patients underwent surgical hip dislocation with a trochanteric slide osteotomy for placement of the allograft. The mean age at surgery was 25.9 years (17 to 44) and mean follow-up was 41.6 months (3 to 74). The mean Harris hip score was significantly better after surgery (p < 0.01) and 13 patients had fair to good outcomes. One patient required a repeat allograft, one patient underwent hip replacement and two patients are awaiting hip replacement. Fresh osteochondral allograft is a reasonable treatment option for hip cartilage defects in young patients.

Cite this article: Bone Joint J 2014;96-B(11 Supple A):11–16.

Aims

Femoroacetabular Junction Impingement (FAI) describes abnormalities in the shape of the femoral head–neck junction, or abnormalities in the orientation of the acetabulum. In the short term, FAI can give rise to pain and disability, and in the long-term it significantly increases the risk of developing osteoarthritis. The Femoroacetabular Impingement Trial (FAIT) aims to determine whether operative or non-operative intervention is more effective at improving symptoms and preventing the development and progression of osteoarthritis.

Resurfacing of the humeral head is commonly used within the UK to treat osteoarthritis (OA) of the shoulder. We present the results of a small prospective randomised study of this procedure using the Global CAP prosthesis with two different coatings, Porocoat and DuoFix hydroxyapatite (HA). We followed two groups of ten patients with OA of the shoulder for two years after insertion of the prosthesis with tantalum marker beads, recording pain, Constant–Murley and American Shoulder and Elbow Surgeons (ASES) outcome scores, and using radiostereometric analysis to assess migration. The outcomes were similar to those of other series, with significant reductions in pain (p = 0.003) and an improvement in the Constant (p = 0.001) and ASES scores (p = 0.006). The mean migration of the prosthesis three months post-operatively was 0.78 mm (0.51 to 1.69) and 0.72 mm (0.33 to 1.45) for the Porocoat and DuoFix groups, respectively. Analysis of variance indicated that the rate of migration reached a plateau after three months post-operatively in both groups. At follow-up of two years the mean migration was 1 mm (sd 1 (0.25 to 3.32)); in the Porocoat group and 0.8 mm (sd 0.4 (0.27 to 1.45)) in the DuoFix HA group. Significant migration of the prosthesis was seen in one patient who had received an anterior humeral bone graft. This prosthesis was later revised after 2.7 years.

The addition of a coating of HA to the sintered surface does not improve fixation of this prosthesis.

Cite this article: Bone Joint J 2014;96-B:1077–81.

The August 2014 Foot & Ankle Roundup360 looks at: calcaneotibial nail in ankle fractures; reamer irrigator aspirator for ankle fusion; periprosthetic bone infection; infection in ankle fixation; cheap and cheerful OK in MTP fusion plates; sliding fibular graft for peroneal tendon pathology and fusion for failed ankle replacement.

Obesity is a global epidemic of 2.1 billion people and a well known cause of osteoarthritis. Joint replacement in the obese attracts more complications, poorer outcomes and higher revision rates. It is a reversible condition and the fundamental principles of dealing with reversible medical conditions prior to elective total joint replacement should apply to obesity. The dilemma for orthopaedic surgeons is when to offer surgery in the face of a reversible condition, which if treated may obviate joint replacement and reduce the risk and severity of obesity related disease in both the medical arena and the field of orthopaedics.

Treatment strategies for osteoarthritis most commonly involve the removal or replacement of damaged joint tissue. Relatively few treatments attempt to arrest, slow down or reverse the disease process. Such options include peri-articular osteotomy around the hip or knee, and treatment of femoro-acetabular impingement, where early intervention may potentially alter the natural history of the disease. A relatively small proportion of patients with osteoarthritis have a clear predisposing factor that is both suitable for modification and who present early enough for intervention to be deemed worthwhile. This paper reviews recent advances in our understanding of the pathology, imaging and progression of early osteoarthritis.

The August 2014 Trauma Roundup³⁶⁰ looks at: On-table CT for calcaneal fractures; timing of femoral fracture surgery and outcomes; salvage arthroplasty for failed internal fixation of the femoral neck; screw insertion in osteoporotic bone; fibular intramedullary nailing on the ascendant; posterior wall acetabular fractures not all that innocent; bugs, plating and resistance and improving outcomes in olecranon tension band wiring.

This retrospective study describes the long-term results of core decompression and placement of a non-vascularised bone graft in the management of avascular necrosis of the femoral head. We treated 80 hips in 65 patients, 18 by a cortical tibial autograft and 62 by a fibular allograft. The mean age of the patients was 36 years (sd 13.2). A total of 78 hips were available for evaluation of which pre-operatively six were Ficat-Arlet stage 0, three stage I, 31 stage IIA, 16 stage IIB, 13 stage III and nine stage IV.

A total of 34 hips (44%) were revised at a mean of four years (sd 3.8). Survivorship analysis using a clinical end-point showed a survival rate of 59% five years after surgery. We found a significant difference (p = 0.002) in survivorship, when using a clinical and radiological end-point, between the two grafts, in favour of the tibial autograft. We considered this difference to be the result of the better quality and increased volume of tibial bone compared with that from the trochanteric region used with the fibular allograft.

This is a relatively simple, extra-articular and reproducible procedure. In our view core decompression, removal of the necrotic tissue and packing of the cancellous grafts into the core track are vital parts of the procedure.

This short contribution aims to explain how intervertebral disc ‘degeneration’ differs from normal ageing, and to suggest how mechanical loading and constitutional factors interact to cause disc degeneration and prolapse. We suggest that disagreement on these matters in medico-legal practice often arises from a misunderstanding of the nature of ‘soft-tissue injuries’.

Chondral damage to the knee is common and, if left untreated, can proceed to degenerative osteoarthritis. In symptomatic patients established methods of management rely on the formation of fibrocartilage which has poor resistance to shear forces. The formation of hyaline or hyaline-like cartilage may be induced by implanting autologous, cultured chondrocytes into the chondral or osteochondral defect.

Autologous chondrocyte implantation may be used for full-thickness chondral or osteochondral injuries which are painful and debilitating with the aim of replacing damaged cartilage with hyaline or hyaline-like cartilage, leading to improved function. The intermediate and long-term functional and clinical results are promising.

We provide a review of autologous chondrocyte implantation and describe our experience with the technique at our institution with a mean follow-up of 32 months (1 to 9 years).

The procedure is shown to offer statistically significant improvement with advantages over other methods of management of chondral defects.

Autologous chondrocyte implantation (ACI) and mosaicplasty are methods of treating symptomatic articular cartilage defects in the knee. This study represents the first long-term randomised comparison of the two techniques in 100 patients at a minimum follow-up of ten years. The mean age of the patients at the time of surgery was 31.3 years (16 to 49); the mean duration of symptoms pre-operatively was 7.2 years (9 months to 20 years). The lesions were large with the mean size for the ACI group being 440.9 mm² (100 to 1050) and the mosaicplasty group being 399.6 mm² (100 to 2000). Patients had a mean of 1.5 previous operations (0 to 4) to the articular cartilage defect. Patients were assessed using the modified Cincinnati knee score and the Stanmore-Bentley Functional Rating system. The number of patients whose repair had failed at ten years was ten of 58 (17%) in the ACI group and 23 of 42 (55%) in the mosaicplasty group (p < 0.001).

The functional outcome of those patients with a surviving graft was significantly better in patients who underwent ACI compared with mosaicplasty (p = 0.02).

Autologous chondrocyte implantation is an option in the treatment of full-thickness chondral or osteochondral injuries which are symptomatic. The goal of surgery and rehabilitation is the replacement of damaged cartilage with hyaline or hyaline-like cartilage, producing improved levels of function and preventing early osteoarthritis. The intermediate results have been promising in terms of functional and clinical improvement.

Our aim was to explore the hypothesis that the histological quality of the repair tissue formed after autologous chondrocyte implantation improved with increasing time after implantation.

In all, 248 patients who had undergone autologous chondrocyte implantation had biopsies taken of the repair tissue which then underwent histological grading. Statistical analysis suggested that with doubling of the time after implantation the likelihood of a favourable histological outcome was increased by more than fourfold (p < 0.001).

Cartilage repair in terms of replacement, or regeneration of damaged or diseased articular cartilage with functional tissue, is the ‘holy grail’ of joint surgery. A wide spectrum of strategies for cartilage repair currently exists and several of these techniques have been reported to be associated with successful clinical outcomes for appropriately selected indications. However, based on respective advantages, disadvantages, and limitations, no single strategy, or even combination of strategies, provides surgeons with viable options for attaining successful long-term outcomes in the majority of patients. As such, development of novel techniques and optimisation of current techniques need to be, and are, the focus of a great deal of research from the basic science level to clinical trials. Translational research that bridges scientific discoveries to clinical application involves the use of animal models in order to assess safety and efficacy for regulatory approval for human use. This review article provides an overview of animal models for cartilage repair.

Cite this article: Bone Joint Res 2014;4:89–94.

Cementless acetabular fixation has demonstrated superior long-term durability in total hip replacement, but most series have studied implants with porous metal surfaces. We retrospectively evaluated the results of 100 consecutive patients undergoing total hip replacement where a non-porous Allofit component was used for primary press-fit fixation.

This implant is titanium alloy, grit-blasted, with a macrostructure of forged teeth and has a biradial shape. A total of 81 patients (82 hips) were evaluated at final follow-up at a mean of 10.1 years (8.9 to 11.9). The Harris Hip Score improved from a mean 53 points (23 to 73) pre-operatively to a mean of 96 points (78 to 100) at final review. The osseointegration of all acetabular components was radiologically evaluated with no evidence of loosening. The survival rate with revision of the component as the endpoint was 97.5% (95% confidence interval 94 to 100) after 11.9 years. Radiolucency was found in one DeLee-Charnley zone in four acetabular components. None of the implants required revision for aseptic loosening. Two patients were treated for infection, one requiring a two-stage revision of the implant. One femoral stem was revised for osteolysis due to the production of metal wear debris, but the acetabular shell did not require revision.

This study demonstrates that a non-porous titanium acetabular component with adjunct surface fixation offers an alternative to standard porous-coated implants.

This preliminary study evaluates a combination of bone morphogenetic protein (BMP)-7 and non-vascularised autologous fibular grafting (AFG) for the treatment of osteonecrosis of the femoral head.

BMP-7/AFG combination was applied in seven pre-collapse femoral heads (five Steinberg stage II, two stage III) in six patients. Pre- and post-operative evaluation included clinical (Harris hip score (HHS), visual analogue scale (VAS) for pain) and radiological assessment (radiographs, quantitative CT) at a mean follow-up of 4 years (2 to 5.5).

A marked improvement of function (mean HHS increase of 49.2) and decrease of pain level (mean VAS decrease of 5) as well as retention of the sphericity of the femoral head was noted in five hips at the latest follow-up, while signs of consolidation were apparent from the third post-operative month. One patient (two hips) required bilateral total hip replacement at one year post-operatively. In the series as a whole, quantitative-CT evaluation revealed similar densities between affected and normal bone. Heterotopic ossification was observed in four hips, without compromise of the clinical outcome.

In this limited series AFG/BMP-7 combination proved a safe and effective method for the treatment of femoral head osteonecrosis, leading to early consolidation of the AFG and preventing collapse in five of seven hips, while the operative time and post-operative rehabilitation period were much shorter compared with free vascularised fibular grafts.

Cite this article: Bone Joint J 2014;96-B:31–5.

Antegrade nailing of proximal humeral fractures using a straight nail can damage the bony insertion of the supraspinatus tendon and may lead to varus failure of the construct. In order to establish the ideal anatomical landmarks for insertion of the nail and their clinical relevance we analysed CT scans of bilateral proximal humeri in 200 patients (mean age 45.1 years (sd 19.6; 18 to 97) without humeral fractures. The entry point of the nail was defined by the point of intersection of the anteroposterior and lateral vertical axes with the cortex of the humeral head. The critical point was defined as the intersection of the sagittal axis with the medial limit of the insertion of the supraspinatus tendon on the greater tuberosity. The region of interest, i.e. the biggest entry hole that would not encroach on the insertion of the supraspinatus tendon, was calculated setting a 3 mm minimal distance from the critical point. This identified that 38.5% of the humeral heads were categorised as ‘critical types’, due to morphology in which the predicted offset of the entry point would encroach on the insertion of the supraspinatus tendon that may damage the tendon and reduce the stability of fixation.

We therefore emphasise the need for ‘fastidious’ pre-operative planning to minimise this risk.

Cite this article: Bone Joint J 2014;96-B:249–53.

The February 2014 Foot & Ankle Roundup³⁶⁰ looks at: optimal medial malleolar fixation; resurfacing in the talus; predicting outcome in mobility ankles; whether mal-aligned ankles can be successfully replaced; cartilage colonisation in bipolar ankle grafts; CTs and proof of fusion; recalcitrant Achilles tendinopathy; and recurrent fifth metatarsal stress fractures.