Objectives

To assess the effectiveness of a modified tibial tubercle osteotomy as a treatment for arthroscopically diagnosed chondromalacia patellae.

Arteriovenous fistula formation after a closed extremity fracture is rare. We present the case of an 11-year-old boy who developed an arteriovenous fistula between the anterior tibial artery and popliteal vein after closed fractures of the proximal tibia and fibula. The fractures were treated by closed reduction and casting. A fistula was diagnosed 12 weeks after the injury. It was treated by embolisation with coils. Subsequent angiography and ultrasonography confirmed patency of the popliteal vein and anterior and posterior tibial and peroneal arteries, with no residual shunting through the fistula. The fractures healed uneventfully and he returned to full unrestricted activities 21 weeks after his injury.

Progressive retroversion of a cemented stem is predictive of early loosening and failure. We assessed the relationship between direct post-operative stem anteversion, measured with CT, and the resulting rotational stability, measured with repeated radiostereometric analysis over ten years. The study comprised 60 cemented total hip replacements using one of two types of matt collared stem with a rounded cross-section. The patients were divided into three groups depending on their measured post-operative anteversion (< 10°, 10° to 25°, >  25°). There was a strong correlation between direct post-operative anteversion and later posterior rotation. At one year the < 10° group showed significantly more progressive retroversion together with distal migration, and this persisted to the ten-year follow-up. In the < 10° group four of ten stems (40%) had been revised at ten years, and an additional two stems (20%) were radiologically loose. In the ‘normal’ (10° to 25°) anteversion group there was one revised (3%) and one loose stem (3%) of a total of 30 stems, and in the > 25° group one stem (5%) was revised and another loose (5%) out of 20 stems. This poor outcome is partly dependent on the design of this prosthesis, but the results strongly suggest that the initial rotational position of cemented stems during surgery affects the subsequent progressive retroversion, subsidence and eventual loosening. The degree of retroversion may be sensitive to prosthetic design and stem size, but < 10° of anteversion appears deleterious to the long-term outcome for cemented hip prosthetic stems.

Cite this article: Bone Joint J 2013;95-B:23–30.

High-pressure injection injuries occur infrequently but are usually work-related and involve the non-dominant hand. The neck is a very rare site for such an injury. We describe the management of a 36-year-old man with a high-pressure grease-gun injection injury to his neck causing a cervical spinal cord injury. He developed severe motor and sensory changes which were relieved by surgical removal of the grease through anterior and posterior approaches.

Plasma levels of cobalt and chromium ions and Metal Artefact Reduction Sequence (MARS)-MRI scans were performed on patients with 209 consecutive, unilateral, symptomatic metal-on-metal (MoM) hip arthroplasties. There was wide variation in plasma cobalt and chromium levels, and MARS-MRI scans were positive for adverse reaction to metal debris (ARMD) in 84 hips (40%). There was a significant difference in the median plasma cobalt and chromium levels between those with positive and negative MARS-MRI scans (p < 0.001). Compared with MARS-MRI as the potential reference standard for the diagnosis of ARMD, the sensitivity of metal ion analysis for cobalt or chromium with a cut-off of > 7 µg/l was 57%. The specificity was 65%, positive predictive value was 52% and the negative predictive value was 69% in symptomatic patients. A lowered threshold of > 3.5 µg/l for cobalt and chromium ion levels improved the sensitivity and negative predictive value to 86% and 74% but at the expense of specificity (27%) and positive predictive value (44%).

Metal ion analysis is not recommended as a sole indirect screening test in the surveillance of symptomatic patients with a MoM arthroplasty. The investigating clinicians should have a low threshold for obtaining cross-sectional imaging in these patients, even in the presence of low plasma metal ion levels.

The bicompartmental acetabulum is one of the morphological changes which may be seen in children with Legg-Calvé-Perthes’ disease. Three-dimensional CT and MRI were used to analyse the detailed morphology of the acetabulum with special reference to its inner surface, in 16 patients with Perthes’ disease and a bicompartmental acetabulum.

The bicompartmental appearance was seen on the coronal plane image through the acetabular fossa. The lunate surface was seen to grow laterally resulting in an increased mediolateral thickness of the triradiate cartilage. On the horizontal plane images, the acetabular fossa had deepened and had a distinct prominence at its posterior border. The combination of these morphological changes resulted in a bicompartmental appearance on plain radiography. Acetabular bicompartmentalisation appears to be the result of an imbalance of growth between the cartilage-covered lunate surface and the cartilage-devoid acetabular fossa.

The inherent challenges of total hip replacement (THR) in children include the choice of implant for the often atypical anatomical morphology, its fixation to an immature growing skeleton and the bearing surface employed to achieve a successful long-term result. We report the medium-term results of 52 consecutive uncemented THRs undertaken in 35 paediatric patients with juvenile idiopathic arthritis. The mean age at the time of surgery was 14.4 years (10 to 16). The median follow-up was 10.5 years (6 to 15). During the study period 13 THRs underwent revision surgery. With revision as an endpoint, subgroup analysis revealed 100% survival of the 23 ceramic-on-ceramic THRs and 55% (16 of 29) of the metal- or ceramic-on-polyethylene. This resulted in 94% (95% CI 77.8 to 98.4) survivorship of the femoral component and 62% (95% CI 41.0 to 78.0) of the acetabular component. Revision of the acetabular component for wear and osteolysis were the most common reasons for failure accounting for 11 of the 13 revisions.

The success seen in patients with a ceramic-on-ceramic articulation seems to indicate that this implant strategy has the potential to make a major difference to the long-term outcome in this difficult group of patients.

We reviewed 212 consecutive patients with adolescent idiopathic scoliosis who underwent posterior spinal arthrodesis using all pedicle screw instrumentation in terms of clinical, radiological and Scoliosis Research Society (SRS)-22 outcomes. In Group 1 (51 patients), the correction was performed over two rods using bilateral segmental pedicle screws. In Group 2 (161 patients), the correction was performed over one rod using unilateral segmental pedicle screws with the second ^{rod providing stability of the construct through two-level screw fixation at proximal and distal ends. The mean age at surgery was 14.8 years in both groups. Comparison between groups showed no significant differences with regard to age and Risser grade at surgery, pre- and post-operative scoliosis angle, coronal Cobb correction, length of hospital stay and SRS scores. Correction of upper thoracic curves was significantly better in Group 1 (p = 0.02). Increased surgical time and intra-operative blood loss was recorded in Group 1 (p < 0.001 and p = 0.04, respectively). The implant cost was reduced by mean 35% in Group 2 due to the lesser number of pedicle screws.}

Unilateral and bilateral pedicle screw techniques have both achieved excellent deformity correction in adolescent patients with idiopathic scoliosis, which was maintained at two-year follow-up. This has been associated with high patient satisfaction and low complication rates.

It has been suggested that an increased posterior tibial slope (PTS) and a narrow notch width index (NWI) increase the risk of anterior cruciate ligament (ACL) injury. The aim of this study was to establish why there are conflicting reports on their significance. A total of fifty patients with a ruptured ACL and 50 patients with an intact ACL were included in the study. The group with ACL rupture had a statistically significantly increased PTS (p < 0.001) and a smaller NWI (p < 0.001) than the control group. When a high PTS and/or a narrow NWI were defined as risk factors for an ACL rupture, 80% of patients had at least one risk factor present; only 24% had both factors present. In both groups the PTS was negatively correlated to the NWI (correlation coefficient = -0.28, p = 0.0052). Using a univariate model, PTS and NWI appear to be correlated to rupture of the ACL. Using a logistic regression model, the PTS (p = 0.006) and the NWI (p < 0.0001) remain significant risk factors. From these results, either a steep PTS or a narrow NWI predisposes an individual to ACL injury. Future studies should consider these factors in combination rather than in isolation.

In this prospective study a total of 80 consecutive Chinese patients with Crowe type I or II developmental dysplasia of the hip were randomly assigned for hip resurfacing arthroplasty (HRA) or total hip replacement (THR).

Three patients assigned to HRA were converted to THR, and three HRA patients and two THR patients were lost to follow-up. This left a total of 34 patients (37 hips) who underwent HRA and 38 (39 hips) who underwent THR. The mean follow-up was 59.4 months (52 to 70) in the HRA group and 60.6 months (50 to 72) in the THR group. There was no failure of the prosthesis in either group. Flexion of the hip was significantly better after HRA, but there was no difference in the mean post-operative Harris hip scores between the groups. The mean size of the acetabular component in the HRA group was significantly larger than in the THR group (49.5 mm vs 46.1 mm, p = 0.001). There was no difference in the mean abduction angle of the acetabular component between the two groups.

Although the patients in this series had risk factors for failure after HRA, such as low body weight, small femoral heads and dysplasia, the clinical results of resurfacing in those with Crowe type I or II hip dysplasia were satisfactory. Patients in the HRA group had a better range of movement, although neck-cup impingement was observed. However, more acetabular bone was sacrificed in HRA patients, and it is unclear whether this will have an adverse effect in the long term.

In the majority of patients with slipped upper femoral epiphysis only one hip is involved at primary diagnosis. However, the contralateral hip often becomes involved over time. There are no reliable factors predicting a contralateral slip. Whether or not the contralateral hip should undergo prophylactic fixation is a matter of controversy. We present a number of essential points that have to be considered both when choosing to fix the contralateral hip prophylactically as well as when refraining from surgery and instead following the patients with repeat radiographs.

Crescent fracture dislocations are a well-recognised subset of pelvic ring injuries which result from a lateral compression force. They are characterised by disruption of the sacroiliac joint and extend proximally as a fracture of the posterior iliac wing. We describe a classification with three distinct types. Type I is characterised by a large crescent fragment and the dislocation comprises no more than one-third of the sacroiliac joint, which is typically inferior. Type II fractures are associated with an intermediate-size crescent fragment and the dislocation comprises between one- and two-thirds of the joint. Type III fractures are associated with a small crescent fragment where the dislocation comprises most, but not all of the joint. The principal goals of surgical intervention are the accurate and stable reduction of the sacroiliac joint. This classification proves useful in the selection of both the surgical approach and the reduction technique. A total of 16 patients were managed according to this classification and achieved good functional results approximately two years from the time of the index injury. Confounding factors compromise the summary short-form-36 and musculoskeletal functional assessment instrument scores, which is a well-recognised phenomenon when reporting the outcome of high-energy trauma.

We have previously described the mid- to long-term results of conventional simple varus intertrochanteric osteotomy for osteonecrosis of the femoral head, showing that 19 of the 26 hips had good or excellent results. We extended the follow-up to a mean of 18.1 years (10.5 to 26) including a total of 34 hips in 28 patients, with a mean age at surgery of 33 years (19 to 53). There were 18 men and ten women and 25 hips (74%) had a satisfactory result with a Harris hip score ≥ 80. In all, six hips needed total hip replacement (THR) or hemiarthroplasty. The collapse of the femoral head or narrowing of the joint space was found to have progressed in nine hips (26%). Leg shortening after osteotomy was a mean of 19 mm (8 to 36). With conversion to THR or hemiarthroplasty as the endpoint, the ten-year survival rate was 88.2% (95% confidence interval (CI) 82.7 to 93.7) and the 20-year survival rate was 79.7% (95% CI 72.1 to 87.3); four hips were converted at ten years and other two hips were converted at 20 years.

Shortening of the leg after osteotomy remains a concern; however, the conventional varus half-wedge osteotomy provides favourable long-term results in hips with less than two-thirds of the medial part of the femoral head affected by necrotic bone and with normal bone superolaterally.

The management of nonunion following high tibial osteotomy by total knee replacement (TKR) has been reported previously. We have extended the treatment to embrace cases with an infected high tibial osteotomy by performing an initial debridement with a period of antibiotic treatment followed by TKR. We have reviewed the results of seven knees in six patients with a mean follow-up of 40.5 months (20 to 57) after the staged TKR. At the latest follow-up, all the pseudarthroses had healed and there had been no recurrence of infection. The mean Hospital for Special Surgery knee score improved from 51.2 (35 to 73) to a mean of 91.7 (84 to 98) at final review.

Management of nonunion following high tibial osteotomy with a TKR can be extended to infected cases when treated in two stages with a debridement and antibiotic therapy prior to TKR.

In the management of a pelvic fracture prompt recognition of an unstable fracture pattern is important in reducing mortality and morbidity. It is believed that a fracture of the transverse process of L5 is a predictor of pelvic fracture instability. However, there is little evidence in the literature to support this view. The aim of this study was to determine whether a fracture of the transverse process of L5 is a reliable predictor of pelvic fracture instability.

We reviewed our hospital trauma database and identified 80 patients who sustained a pelvic fracture between 2006 and 2010. There were 32 women and 48 men with a mean age of 40 years (10 to 96). Most patients were injured in a road traffic accident or as a result of a fall from a height. A total of 41 patients (51%) had associated injuries. The pelvic fractures were categorised according to the Burgess and Young classification. There were 45 stable and 35 unstable fractures. An associated fracture of the transverse process of L5 was present in 17 patients; 14 (40%) of whom had an unstable fracture pattern. The odds ratio for an unstable fracture of the pelvis in the presence of a fracture of the transverse process of L5 was 9.3 and the relative risk was 2.5.

A fracture of the transverse process of L5 in the presence of a pelvic fracture is associated with an increased risk of instability of the pelvic fracture. Its presence should alert the attending staff to this possibility.

In this prospective study we studied the effect of the inclination angle of the acetabular component on polyethylene wear and component migration in cemented acetabular sockets using radiostereometric analysis.

A total of 120 patients received either a cemented Reflection All-Poly ultra-high-molecular-weight polyethylene or a cemented Reflection All-Poly highly cross-linked polyethylene acetabular component, combined with either cobalt–chrome or Oxinium femoral heads. Femoral head penetration and migration of the acetabular component were assessed with repeated radiostereometric analysis for two years. The inclination angle was measured on a standard post-operative anteroposterior pelvic radiograph. Linear regression analysis was used to determine the relationship between the inclination angle and femoral head penetration and migration of the acetabular component.

We found no relationship between the inclination angle and penetration of the femoral head at two years’ follow-up (p = 0.9). Similarly, our data failed to reveal any statistically significant correlation between inclination angle and migration of these cemented acetabular components (p = 0.07 to p = 0.9).

We describe 22 cases of bizarre parosteal osteochondromatous proliferation, or Nora’s lesion. These are surface-based osteocartilaginous lesions typically affecting the hands and feet. All patients were identified from the records of a regional bone tumour unit and were treated between 1985 and 2009. Nine lesions involved the metacarpals, seven the metatarsals, one originated from a sesamoid bone of the foot and five from long bones (radius, ulna, tibia, and femur in two). The mean age of the patients was 31.8 years (6 to 66), with 14 men and eight women. Diagnosis was based on the radiological and histological features. The initial surgical treatment was excision in 21 cases and amputation of a toe in one. The mean follow-up was for 32 months (12 to 162). Recurrence occurred in six patients (27.3%), with a mean time to recurrence of 49 months (10 to 120). Two of the eight patients with complete resection margins developed a recurrence (25.0%), compared with four of 14 with a marginal or incomplete resection (28.6%).

Given the potential surgical morbidity inherent in resection, our data suggest that there may be a role for a relatively tissue-conserving approach to the excision of these lesions.

The purpose of this study was to describe the anatomical distribution and incidence of fatigue injuries of the femur in physically-active young adults, based upon MRI studies. During a period of 70 months, 1857 patients with exercise-induced pain in the femur underwent MRI of the pelvis, hips, femora, and/or knees.

Of these, 170 patients had a total of 185 fatigue injuries, giving an incidence of 199 per 100 000 person-years. Bilateral injuries occurred in 9% of patients. The three most common sites affected were the femoral neck (50%), the condylar area (24%) and the proximal shaft (18%). A fatigue reaction was seen in 57%, and a fracture line in 22%. There was a statistical correlation between the severity of the fatigue injury and the duration of pain (p = 0.001). The location of the pain was normally at the site of the fatigue injury. Fatigue injuries of the femur appear to be relatively common in physically-active patients.

The aim of this study was to determine whether an osteoplasty of the femoral neck performed at the same time as an intertrochanteric Imhäuser osteotomy led to an improved functional outcome or increased morbidity. A total of 20 hips in 19 patients (12 left, 8 right, 13 male, 6 female), who underwent an Imhäuser intertrochanteric osteotomy following a slipped capital femoral epiphysis were assessed over an eight-year period. A total of 13 hips in 13 patients had an osteoplasty of the femoral neck at the same time. The remaining six patients (seven hips) had intertrochanteric osteotomy alone. The mean age was 15.3 years (13 to 20) with a mean follow-up of 57.8 months (15 to 117); 19 of the slips were severe (Southwick grade III) and one was moderate (grade II), with a mean slip angle of 65.3° (50° to 80°); 17 of the slips were stable and three unstable at initial presentation. The mean Non-Arthritic Hip Scores (NAHS) in patients who underwent osteoplasty was 91.7 (76.3 to 100) and the mean NAHS in patients who did not undergo osteoplasty was 76.6 (41.3 to 100) (p = 0.056). Two patients required a subsequent arthroplasty and neither of these patients had an osteoplasty. No hips developed osteonecrosis or chondrolysis, and there was no increase in complications related to the osteoplasty. We recommend that for patients with a slipped upper femoral epiphysis undergoing an intertrochanteric osteotomy, the addition of an osteoplasty of the femoral neck should be considered.

Cite this article: Bone Joint J 2014;96-B:1119–23.

The aim of this retrospective cohort study was to identify any difference in femoral offset as measured on pre-operative anteroposterior (AP) radiographs of the pelvis, AP radiographs of the hip and corresponding CT scans in a consecutive series of 100 patients with primary end-stage osteoarthritis of the hip (43 men and 57 women with a mean age of 61 years (45 to 74) and a mean body mass index of 28 kg/m² (20 to 45)).

Patients were positioned according to a standardised protocol to achieve reproducible projection and all images were calibrated. Inter- and intra-observer reliability was evaluated and agreement between methods was assessed using Bland-Altman plots.

In the entire cohort, the mean femoral offset was 39.0 mm (95% confidence interval (CI) 37.4 to 40.6) on radiographs of the pelvis, 44.0 mm (95% CI 42.4 to 45.6) on radiographs of the hip and 44.7 mm (95% CI 43.5 to 45.9) on CT scans. AP radiographs of the pelvis underestimated femoral offset by 13% when compared with CT (p < 0.001). No difference in mean femoral offset was seen between AP radiographs of the hip and CT (p = 0.191).

Our results suggest that femoral offset is significantly underestimated on AP radiographs of the pelvis but can be reliably and accurately assessed on AP radiographs of the hip in patients with primary end-stage hip osteoarthritis.

We, therefore, recommend that additional AP radiographs of the hip are obtained routinely for the pre-operative assessment of femoral offset when templating before total hip replacement.