Aims

A fracture of the medial tibial plateau is a serious complication of Oxford mobile-bearing unicompartmental knee arthroplasty (OUKA). The risk of these fractures is reportedly lower when using components with a longer keel-cortex distance (KCDs). The aim of this study was to examine how slight varus placement of the tibial component might affect the KCDs, and the rate of tibial plateau fracture, in a clinical setting.

Aims

The extensive variation in axial rotation of tibial components can lead to coronal plane malalignment. We analyzed the change in coronal alignment induced by tray malrotation.

Internal lengthening devices in the femur lengthen along the anatomical axis, potentially creating lateral shift of the mechanical axis. We aimed to determine whether femoral lengthening along the anatomical axis has an inadvertent effect on lower limb alignment. Isolated femoral lengthening using the Intramedullary Skeletal Kinetic Distractor was performed in 27 femora in 24 patients (mean age 32 years (16 to 57)). Patients who underwent simultaneous realignment procedures or concurrent tibial lengthening, or who developed mal- or nonunion, were excluded. Pre-operative and six-month post-operative radiographs were used to measure lower limb alignment. The mean lengthening achieved was 4.4 cm (1.5 to 8.0). In 26 of 27 limbs, the mechanical axis shifted laterally by a mean of 1.0 mm/cm of lengthening (0 to 3.5). In one femur that was initially in varus, a 3 mm medial shift occurred during a lengthening of 2.2 cm.

In a normally aligned limb, intramedullary lengthening along the anatomical axis of the femur results in a lateral shift of the mechanical axis by approximately 1 mm for each 1 cm of lengthening.

1. A conservative approach to the varus deformity of anaesthetic feet in infants with myelomeningocele is advocated. Thirty-three of thirty-five varus feet treated by this method, supplemented when necessary by a minor operation to correct equinus, responded satisfactorily in this prospective study of twenty-four infants treated from birth.

2. A rotation flap incision has proved of considerable advantage in the rare instances when an extensive medial release is required.

1. Tarsal coalition often presents with the clinical picture of a peroneal spastic flat foot, but may present with a painful varus foot and spasm of the tibial muscles.

2. Three cases of tibialis spastic varus foot are described with a calcaneo-navicular bar as the associated anomaly.

3. Complete excision of the bar with interposition of the origin of the extensor digitorum brevis muscle appears to be a satisfactory method of treatment when carried out at a sufficiently early age.

We have analysed retrospectively the relationship between the axial parameters of alignment of the lower limb and the recurrence of varus deformity after high tibial osteotomy. We studied 29 patients (37 knees) with a mean age at surgery of 66 years. The mean follow-up was for 7.4 years (5 to 10.5). Recurrence of varus deformity was defined as an increase in the femorotibial angle of 3° or more, compared with that obtained six months after the operation. There were four patients (four knees) with recurrence of varus deformity. They had a greater varus inclination of the distal femur than those without varus recurrence.

An association between varus inclination of the distal femur and horizontal obliquity of the joint surface was observed. Excessive obliquity prevents the shift of weight-bearing to the lateral compartment, and may cause a recurrence of varus deformity after high tibial osteotomy.

1. Three children with metatarsus adductus varus have been found to have ball and socket ankle joints.

2. The effect of this finding on treatment is discussed.

We studied the morphological changes in the proximal femur in 42 patients (42 hips) who had had varus derotation osteotomy of the upper femur for residual acetabular dysplasia and congenital subluxation of the hip and who did not show deformity of the head of the femur. In 19 patients the alignment of the whole leg was examined. The femoral neck-shaft angle (FNSA) at the final examination was unrelated to that immediately after operation or to the state of the acetabulum at that time. The postoperative FNSA was not related to the final result but the CE angle obtained at surgery influenced the outcome. The femoral length did not differ significantly between the unaffected and affected sides. Significant differences were found in the femorotibial angle (176.6 degrees v 174.5 degrees) and in the point of intersection between the mechanical axis and knee (65.0% v 57.2%).

Aims. Total knee arthroplasty (TKA) may provoke ankle symptoms. The aim of this study was to validate the impact of the preoperative mechanical tibiofemoral angle (mTFA), the talar tilt (TT) on ankle symptoms after TKA, and assess changes in the range of motion (ROM) of the subtalar joint, foot posture, and ankle laxity. Methods. Patients who underwent TKA from September 2020 to September 2021 were prospectively included. Inclusion criteria were primary end-stage osteoarthritis (Kellgren-Lawrence stage IV) of the knee. Exclusion criteria were missed follow-up visit, post-traumatic pathologies of the foot, and neurological disorders. Radiological angles measured included the mTFA, hindfoot alignment view angle, and TT. The Foot Function Index (FFI) score was assessed. Gait analyses were conducted to measure mediolateral changes of the gait line and ankle laxity was tested using an ankle arthrometer. All parameters were acquired one week pre- and three months postoperatively. Results. A total of 69 patients (varus n = 45; valgus n = 24) underwent TKA and completed the postoperative follow-up visit. Of these, 16 patients (23.2%) reported the onset or progression of ankle symptoms. Varus patients with increased ankle symptoms after TKA had a significantly higher pre- and postoperative TT. Valgus patients with ankle symptoms after TKA showed a pathologically lateralized gait line which could not be corrected through TKA. Patients who reported increased ankle pain neither had a decreased ROM of the subtalar joint nor increased ankle laxity following TKA. The preoperative mTFA did not correlate with the postoperative FFI (r = 0.037; p = 0.759). Conclusion. Approximately one-quarter of the patients developed ankle pain after TKA. If patients complain about ankle symptoms after TKA, standing radiographs of the ankle and a gait analysis could help in detecting a malaligned TT or a pathological gait. Cite this article: Bone Joint J 2023;105-B(11):1159–1167

Aims. The aim of this study was to identify patient- and surgery-related risk factors for sustaining an early periprosthetic fracture following primary total hip arthroplasty (THA) performed using a double-tapered cementless femoral component (Bi-Metric femoral stem; Biomet Inc., Warsaw, Indiana). Patients and Methods. A total of 1598 consecutive hips, in 1441 patients receiving primary THA between January 2010 and June 2015, were retrospectively identified. Level of pre-operative osteoarthritis, femoral Dorr type and cortical index were recorded. Varus/valgus placement of the stem and canal fill ratio were recorded post-operatively. Periprosthetic fractures were identified and classified according to the Vancouver classification. Regression analysis was performed to identify risk factors for early periprosthetic fracture. Results. The mean follow-up was 713 days (1 to 2058). A total of 48 periprosthetic fractures (3.0%) were identified during the follow-up and median time until fracture was 16 days, (interquartile range 10 to 31.5). Patients with femoral Dorr type C had a 5.2 times increased risk of post-operative periprosthetic fracture compared with type B, while female patients had a near significant two times increased risk over time for post-operative fracture. Conclusion. Dorr type C is an independent risk factor for early periprosthetic fracture, following THA using a double tapered cementless stem such as the Bi-Metric. Surgeons should take bone morphology into consideration when planning for primary THA and consider using cemented femoral components in female patients with poor bone quality. Cite this article: Bone Joint J 2017;99-B:451–7

Aims . To assess the effect of high tibial and distal femoral osteotomies (HTO and DFO) on the pressure characteristics of the ankle joint. Materials and Methods. Varus and valgus malalignment of the knee was simulated in human cadaver full-length legs. Testing included four measurements: baseline malalignment, 5° and 10° re-aligning osteotomy, and control baseline malalignment. For HTO, testing was rerun with the subtalar joint fixed. In order to represent half body weight, a 300 N force was applied onto the femoral head. Intra-articular sensors captured ankle pressure. Results. In the absence of restriction of subtalar movement, insignificant migration of the centre of force and changes of maximal pressure were seen at the ankle joint. With restricted subtalar motion, more significant lateralisation of the centre of force were seen with the subtalar joint in varus than in valgus position. Changes in maximum pressure were again not significant. . Conclusion. The re-alignment of coronal plane knee deformities by HTO and DFO altered ankle pressure characteristics. When the subtalar joint was fixed in the varus position, migration of centre of force after HTO was more significant than when the subtalar joint was fixed in valgus. Cite this article: Bone Joint J 2017;99-B:59–65

Aims

Temporary hemiepiphysiodesis (HED) is applied to children and adolescents to correct angular deformities (ADs) in long bones through guided growth. Traditional Blount staples or two-hole plates are mainly used for this indication. Despite precise surgical techniques and attentive postoperative follow-up, implant-associated complications are frequently described. To address these pitfalls, a flexible staple was developed to combine the advantages of the established implants. This study provides the first results of guided growth using the new implant and compares these with the established two-hole plates and Blount staples.

Aims

This scoping review aims to identify patient-related factors associated with a poorer outcome following total ankle arthroplasty (TAA).

We have studied the effect of shortening of the femoral neck and varus collapse on the functional capacity and quality of life of patients who had undergone fixation of an isolated intracapsular fracture of the hip with cancellous screws. After screening 660 patients at four university medical centres, 70 patients with a mean age of 71 years (20 to 90) met the inclusion criteria. Overall, 66% (46 of 70) of the fractures healed with > 5 mm of shortening and 39% (27 of 70) with > 5° of varus. Patients with severe shortening of the femoral neck had significantly lower short form-36 questionnaire (SF-36) physical functioning scores (no/mild (< 5 mm) vs severe shortening (> 10 mm); 74 vs 42 points, p < 0.001). A similar effect was noted with moderate shortening, suggesting a gradient effect (no/mild (< 5 mm) vs moderate shortening (5 to 10 mm); 74 vs 53 points, p = 0.011). Varus collapse correlated moderately with the occurrence of shortening (r = 0.66, p < 0.001). Shortening also resulted in a significantly lower EuroQol questionnaire (EQ5D) index scores (p = 0.05). In a regression analysis shortening of the femoral neck was the only significant variable predictive of a low SF-36 physical functioning score (p < 0.001)

The aim of mechanical alignment in total knee arthroplasty is to align all knees into a fixed neutral position, even though not all knees are the same. As a result, mechanical alignment often alters a patient’s constitutional alignment and joint line obliquity, resulting in soft-tissue imbalance. This annotation provides an overview of how the Coronal Plane Alignment of the Knee (CPAK) classification can be used to predict imbalance with mechanical alignment, and then offers practical guidance for bone balancing, minimizing the need for soft-tissue releases.

Cite this article: Bone Joint J 2024;106-B(6):525–531.

Aims

The aim of this study was to investigate whether anterior pelvic plane-pelvic tilt (APP-PT) is associated with distinct hip pathomorphologies. We asked: is there a difference in APP-PT between young symptomatic patients being evaluated for joint preservation surgery and an asymptomatic control group? Does APP-PT vary among distinct acetabular and femoral pathomorphologies? And does APP-PT differ in symptomatic hips based on demographic factors?