The June 2014 Foot & Ankle Roundup³⁶⁰ looks at: peroneal tendon tears associated with calcaneal fractures; syndesmosis procedure for first ray deformities; thromboprophylaxis not necessary in elective Ilizarov surgery; ankle replacement gaining traction in academic centres; some evidence for PRP and; fusion nailing and osteotomy an effective treatment for symptomatic tibial malunion

We assessed the reliability, accuracy and variability of closed-wedge high tibial osteotomy (HTO) using computer-assisted surgery compared to the conventional technique. A total of 50 closed-wedge HTO procedures were performed using the navigation system, and compared with 50 HTOs that had been performed with the conventional technique. In the navigation group, the mean mechanical axis prior to osteotomy was varus 8.2°, and the mean mechanical axis following fixation was valgus 3.6°. On the radiographs the mean pre-operative mechanical axis was varus 7.3°, and the mean post-operative mechanical axis was valgus 2.1°. There was a positive correlation between the measured data taken under navigation and by radiographs (r > 0.3, p < 0.05). The mean correction angle was significantly more accurate in the navigation group (p < 0.002). The variability of the correction was significantly lower in the navigation group (2.3° vs 3.7°, p = 0,012). We conclude that navigation provides reliable real-time intra-operative information, may increase accuracy, and improves the precision of a closed-wedge HTO.

Aims

Single-event multilevel surgery (SEMLS) has been used as an effective intervention in children with bilateral spastic cerebral palsy (BSCP) for 30 years. To date there is no evidence for SEMLS in adults with BSCP and the intervention remains focus of debate.

This study aimed to evaluate the use of pin leverage in the reduction of Gartland type III supracondylar fractures of the humerus in children. The study comprised 95 children, who were split into three groups according to the type of method of reduction used. Group 1, had an open reduction, group 2, had closed reduction and percutaneous pin fixation and group 3, the pin leverage technique. Each group was analysed according to the time to surgery, the duration of the procedure, the incidence of complications, and the clinical and radiological outcome.

The mean duration of the operative procedure in groups 1, 2 and 3 was 119 minutes (80 to 235), 57 minutes (20 to 110) and 68 minutes (30 to 90), respectively. At a mean follow-up of 30 months (12 to 63) the clinical results were declared excellent or good in all children and the radiological results intermediate in five patients in group 2. The results of the closed reduction using the pin leverage technique was classified as failure in two children.

Our findings lead us to believe that the pin leverage method of reduction gives good results in the treatment of Gartland type III fractures.

Posterolateral rotatory instability is the most common type of symptomatic chronic instability of the elbow. In this condition the forearm complex rotates externally in relation to the humerus, causing posterior subluxation or dislocation of the radial head. The lateral ligament complex, radial head and coronoid process are important constraints to posterolateral rotatory instability, and their disruption is involved in the pathogenesis of this condition. The diagnosis relies on a high index of clinical suspicion, active and passive apprehension tests, and examination under anaesthesia. Surgical treatment has given consistently successful results. Open reconstruction of the lateral ligaments with a tendon graft has been the procedure of choice, with arthroscopic techniques emerging as a potential alternative.

Between 1990 and 2001, 24 children aged between 15 months and 11 years presented with late orthopaedic sequelae after meningococcal septicaemia. The median time to presentation was 32 months (12 to 119) after the acute phase of the disease. The reasons for referral included angular deformity, limb-length discrepancy, joint contracture and problems with prosthetic fitting. Angular deformity with or without limb-length discrepancy was the most common presentation. Partial growth arrest was the cause of the angular deformity. Multiple growth-plate involvement occurred in 14 children. The lower limbs were affected much more often than the upper. Twenty-three children underwent operations for realignment of the mechanical axis and limb-length equalisation. In 15 patients with angular deformity around the knee the deformity recurred. As a result we recommend performing a realignment procedure with epiphysiodesis of the remaining growth plate when correcting angular deformities.

Twenty patients underwent simultaneous bilateral medial unicompartmental knee arthroplasty. Pre-operative hip-knee-ankle alignment and valgus stress radiographs were used to plan the desired post-operative alignment of the limb in accordance with established principles for unicompartmental arthroplasty. In each patient the planned alignment was the same for both knees. Overall, the mean planned post-operative alignment was to 2.3° of varus (0° to 5°).

The side and starting order of surgery were randomised, using conventional instrumentation for one knee and computer-assisted surgery for the opposite side.

The mean variation between the pre-operative plan and the achieved correction in the navigated and the non-navigated limb was 0.9° (sd 1.1; 0° to 4°) and 2.8° (sd 1.4; 1° to 7°), respectively. Using the Wilcoxon signed rank test, we found the difference in variation statistically significant (p < 0.001).

Assessment of lower limb alignment in the non-navigated group revealed that 12 (60%) were within ± 2° of the pre-operative plan, compared to 17 (87%) of the navigated cases.

Computer-assisted surgery significantly improves the post-operative alignment of medial unicompartmental knee arthroplasty compared to conventional techniques in patients undergoing bilateral simultaneous arthroplasty. Improved alignment after arthroplasty is associated with better function and increased longevity.

The options for treatment of the young active patient with isolated symptomatic osteoarthritis of the medial compartment and pre-existing deficiency of the anterior cruciate ligament are limited. The potential longevity of the implant and levels of activity of the patient may preclude total knee replacement, and tibial osteotomy and unicompartmental knee arthroplasty are unreliable because of the ligamentous instability. Unicompartmental knee arthroplasties tend to fail because of wear or tibial loosening resulting from eccentric loading. Therefore, we combined reconstruction of the anterior cruciate ligament with unicompartmental arthroplasty of the knee in 15 patients (ACLR group), and matched them with 15 patients who had undergone Oxford unicompartmental knee arthroplasty with an intact anterior cruciate ligament (ACLI group). The clinical and radiological data at a minimum of 2.5 years were compared for both groups.

The groups were well matched for age, gender and length of follow-up and had no significant differences in their pre-operative scores. At the last follow-up, the mean outcome scores for both the ACLR and ACLI groups were high (Oxford knee scores of 46 (37 to 48) and 43 (38 to 46), respectively, objective Knee Society scores of 99 (95 to 100) and 94 (82 to 100), and functional Knee Society scores of 96 and 96 (both 85 to 100). One patient in the ACLR group needed revision to a total knee replacement because of infection. No patient in either group had radiological evidence of component loosening. The radiological study showed no difference in the pattern of tibial loading between the groups.

The short-term clinical results of combined anterior cruciate ligament reconstruction and unicompartmental knee arthroplasty are excellent. The previous shortcomings of unicompartmental knee arthroplasty in the presence of deficiency of the anterior cruciate ligament appear to have been addressed with the combined procedure. This operation seems to be a viable treatment option for young active patients with symptomatic arthritis of the medial compartment, in whom the anterior cruciate ligament has been ruptured.

The aim of this study was to evaluate the risk factors for dislocation of the bearing after a mobile-bearing Oxford medial unicompartmental knee replacement (UKR) and to test the hypothesis that surgical factors, as measured from post-operative radiographs, are associated with its dislocation

From a total of 480 UKRs performed between 2001 and 2012, in 391 patients with a mean age of 66.5 years (45 to 82) (316 female, 75 male), we identified 17 UKRs where bearing dislocation occurred. The post-operative radiological measurements of the 17 UKRs and 51 matched controls were analysed using conditional logistic regression analysis. The post-operative radiological measurements included post-operative change in limb alignment, the position of the femoral and tibial components, the resection depth of the proximal tibia, and the femoral component-posterior condyle classification.

We concluded that a post-operative decrease in the posterior tibial slope relative to the pre-operative value was the only significant determinant of dislocation of the bearing after medial Oxford UKR (odds ratio 1.881; 95% confidence interval 1.272 to 2.779). A post-operative posterior tibial slope < 8.45° and a difference between the pre-operative and post-operative posterior tibial slope of > 2.19° may increase the risk of dislocation.

Cite this article: Bone Joint J 2014; 96-B:914–22.

The appearance of the ‘grand-piano sign’ on the anterior resected surface of the femur has been considered to be a marker for correct femoral rotational alignment during total knee replacement. Our study was undertaken to assess quantitatively the morphological patterns on the resected surface after anterior femoral resection with various angles of external rotation, using a computer-simulation technique. A total of 50 right distal femora with varus osteoarthritis in 50 Korean patients were scanned using computerised tomography. Computer image software was used to simulate the anterior femoral cut, which was applied at an external rotation of 0°, 3° and 6° relative to the posterior condylar axis, and parallel to the surgical and clinical epicondylar axes in each case. The morphological patterns on the resected surface were quantified and classified as the ‘grand-piano sign’, ‘the boot sign’ and the ‘butterfly sign’. The surgeon can use the analogy of these quantified sign patterns to ensure that a correct rotational alignment has been obtained intra-operatively.

We performed a retrospective review of a consecutive series of 178 Mobility total ankle replacements (TARs) performed by three surgeons between January 2004 and June 2009, and analysed radiological parameters and clinical outcomes in a subgroup of 129 patients. The mean follow-up was 4 years (2 to 6.3). A total of ten revision procedures (5.6%) were undertaken. The mean Ankle Osteoarthritis Scale (AOS) pain score was 17 (0 to 88) and 86% of patients were clinically improved at follow-up. However, 18 patients (18 TARs, 14%) had a poor outcome with an AOS pain score of > 30. A worse outcome was associated with a pre-operative diagnosis of post-traumatic degenerative arthritis. However, no pre- or post-operative radiological parameters were significantly associated with a poor outcome. Of the patients with persistent pain, eight had predominantly medial-sided pain. Thirty TARs (29%) had a radiolucency in at least one zone.

The outcome of the Mobility TAR at a mean of four years is satisfactory in > 85% of patients. However, there is a significant incidence of persistent pain, particularly on the medial side, for which we were unable to establish a cause.

Cite this article: Bone Joint J 2013;95-B:1366–71.

Charcot osteoarthropathy of the foot is a chronic and progressive disease of bone and joint associated with a risk of amputation. The main problems encountered in this process are osteopenia, fragmentation of the bones of the foot and ankle, joint subluxation or even dislocation, ulceration of the skin and the development of deep sepsis. We report our experience of a series of 20 patients with Charcot osteoarthropathy of the foot and ankle treated with an Ilizarov external fixator. The mean age of the group was 30 years (21 to 50). Diabetes mellitus was the underlying cause in 18 patients. Five had chronic ulcers involving the foot and ankle. Each patient had an open lengthening of the tendo Achillis with excision of all necrotic and loose bone from the ankle, subtalar and midtarsal joints when needed. The resulting defect was packed with corticocancellous bone graft harvested from the iliac crest and an Ilizarov external fixator was applied. Arthrodesis was achieved after a mean of 18 weeks (15 to 20), with healing of the skin ulcers. Pin track infection was not uncommon, but no frame had to be removed before the arthrodesis was sound.

Every patient was able to resume wearing regular shoes after a mean of 26.5 weeks (20 to 45).

We performed a prospective, randomised controlled trial of unicompartmental knee arthroplasty comparing the performance of the Acrobot system with conventional surgery. A total of 27 patients (28 knees) awaiting unicompartmental knee arthroplasty were randomly allocated to have the operation performed conventionally or with the assistance of the Acrobot. The primary outcome measurement was the angle of tibiofemoral alignment in the coronal plane, measured by CT. Other secondary parameters were evaluated and are reported.

All of the Acrobot group had tibiofemoral alignment in the coronal plane within 2° of the planned position, while only 40% of the conventional group achieved this level of accuracy. While the operations took longer, no adverse effects were noted, and there was a trend towards improvement in performance with increasing accuracy based on the Western Ontario and McMaster Universities Osteoarthritis Index and American Knee Society scores at six weeks and three months. The Acrobot device allows the surgeon to reproduce a pre-operative plan more reliably than is possible using conventional techniques which may have clinical advantages.

We analysed the clinical and radiological outcomes of a new surgical technique for the treatment of heterozygote post-axial metatarsal-type foot synpolydactyly with HOX-D13 genetic mutations with a mean follow-up of 30.9 months (24 to 42). A total of 57 feet in 36 patients (mean age 6.8 years (2 to 16)) were treated with this new technique, which transfers the distal part of the duplicated fourth metatarsal to the proximal part of the fifth metatarsal. Clinical and radiological assessments were undertaken pre- and post-operatively and any complications were recorded. Final outcomes were evaluated according to the methods described by Phelps and Grogan. Forefoot width was reduced and the lengths of the all reconstructed toes were maintained after surgery. Union was achieved for all the metatarsal osteotomies without any angular deformities. Outcomes at the final assessment were excellent in 51 feet (89%) and good in six (11%). This newly described surgical technique provides for painless, comfortable shoe-wearing after a single, easy-to-perform operation with good clinical, radiological and functional outcomes.

Cite this article: Bone Joint J 2013;95-B:929–34.

The outcome of high tibial osteotomy (HTO) deteriorates with time, and additional procedures may be required. The aim of this study was to compare the clinical and radiological outcomes between unicompartmental knee replacement (UKR) and total knee replacement (TKR) after HTO as well as after primary UKR. A total of 63 patients (63 knees) were studied retrospectively and divided into three groups: UKR after HTO (group A; n = 22), TKR after HTO (group B; n = 18) and primary UKR (group C; n = 22). The Oxford knee score (OKS), Knee Society score (KSS), hip–knee–ankle angles, mechanical axis and patellar height were evaluated pre- and post-operatively. At a mean of 64 months (19 to 180) post-operatively the mean OKS was 43.8 (33 to 49), 43.3 (30 to 48) and 42.5 (29 to 48) for groups A, B and C, respectively (p = 0.73). The mean KSS knee score was 88.8 (54 to 100), 88.11 (51 to 100) and 85.3 (45 to 100) for groups A, B and C, respectively (p = 0.65), and the mean KSS function score was 85.0 (50 to 100) in group A, 85.8 (20 to 100) in group B and 79.3 (50 to 100) in group C (p = 0.48). Radiologically the results were comparable for all groups except for patellar height, with a higher incidence of patella infra following a previous HTO (p = 0.02).

Cite this article: Bone Joint J 2013;95-B:1348–53.

Objectives

The purpose of this study was to compare the results and complications of tibial lengthening over an intramedullary nail with treatment using the traditional Ilizarov method.

In 1937 Blount described a series of 28 patients with ‘Tibia vara’. Since then, a number of deformities in the tibia and the femur have been described in association with this condition.

We analysed 14 children with Blount’s disease who were entered into a cross-sectional study. Their mean age was 10 (2 to 18). They underwent a clinical assessment of the rotational profile of their legs and a CT assessment of the angle of anteversion of their hips (femoral version). We compared our results to previously published controls. A statistically significant increase in femoral anteversion was noted in the affected legs, with on average the femurs in patients with Blount’s disease being 26° more anteverted than those in previously published controls.

We believe this to be a previously unrecognised component of Blount’s disease, and that the marked intoeing seen in the disease may be partly caused by internal femoral version, in addition to the well-recognised internal tibial version.

Permanent growth arrest of the longer bone is an option in the treatment of minor leg-length discrepancies. The use of a tension band plating technique to produce a temporary epiphysiodesis is appealing as it avoids the need for accurate timing of the procedure in relation to remaining growth. We performed an animal study to establish if control of growth in a long bone is possible with tension band plating. Animals (pigs) were randomised to temporary epiphysiodesis on either the right or left tibia. Implants were removed after ten weeks. Both tibiae were examined using MRI at baseline, and after ten and 15 weeks. The median interphyseal distance was significantly shorter on the treated tibiae after both ten weeks (p = 0.04) and 15 weeks (p = 0.04). On T₁-weighted images the metaphyseal water content was significantly reduced after ten weeks on the treated side (p = 0.04) but returned to values comparable with the untreated side at 15 weeks (p = 0.14). Return of growth was observed in all animals after removal of implants.

Temporary epiphysiodesis can be obtained using tension band plating. The technique is not yet in common clinical practice but might avoid the need for the accurate timing of epiphysiodesis.

Cite this article: Bone Joint J 2013;95-B:855–60.

Focal femoral inlay resurfacing has been developed for the treatment of full-thickness chondral defects of the knee. This technique involves implanting a defect-sized metallic or ceramic cap that is anchored to the subchondral bone through a screw or pin. The use of these experimental caps has been advocated in middle-aged patients who have failed non-operative methods or biological repair techniques and are deemed unsuitable for conventional arthroplasty because of their age. This paper outlines the implant design, surgical technique and biomechanical principles underlying their use. Outcomes following implantation in both animal and human studies are also reviewed.

Cite this article: Bone Joint J 2013;95-B:301–4.

The advent of computer-assisted knee replacement surgery has focused interest on the alignment of the components. However, there is confusion at times between the alignment of the limb as a whole and that of the components. The interaction between them is discussed in this article. Alignment is expressed relative to some reference axis or plane and measurements will vary depending on what is selected as the reference. The validity of different reference axes is discussed. Varying prosthetic alignment has direct implications for surrounding soft-tissue tension. In this context the interaction between alignment and soft-tissue balance is explored and the current knowledge of the relationship between alignment and outcome is summarised.