Improvements in the surgical technique of total knee replacement (TKR) are continually being sought. There has recently been interest in three-dimensional (3D) pre-operative planning using magnetic resonance imaging (MRI) and CT. The 3D images are increasingly used for the production of patient-specific models, surgical guides and custom-made implants for TKR.

The users of patient-specific instrumentation (PSI) claim that they allow the optimum balance of technology and conventional surgery by reducing the complexity of conventional alignment and sizing tools. In this way the advantages of accuracy and precision claimed by computer navigation techniques are achieved without the disadvantages of additional intra-operative inventory, new skills or surgical time.

This review describes the terminology used in this area and debates the advantages and disadvantages of PSI.

We investigated the development of CT-based bony radiological parameters associated with femoroacetabular impingement (FAI) in a paediatric and adolescent population with no known orthopaedic hip complaints. We retrospectively reformatted and reoriented 225 abdominal CTs into standardised CT pelvic images with neutral pelvic tilt and inclination (244 female and 206 male hips) in patients ranging from two to 19 years of age (mean 10.4 years). The Tönnis angle, acetabular depth ratio, lateral centre–edge angle, acetabular version and α-angle were assessed.

Acetabular measurements demonstrated increased acetabular coverage with age and/or progressive ossification of the acetabulum. The α-angle decreased with age and/or progressive cortical bone development and resultant narrowing of the femoral neck. Cam and pincer morphology occurred as early as ten and 12 years of age, respectively, and their prevalence in the adolescent patient population is similar to that reported in the adult literature. Future aetiological studies of FAI will need to focus on the early adolescent population.

Cite this article: Bone Joint J 2013;95-B:598–604.

Giant cell tumours (GCTs) of the small bones of the hands and feet are rare. Small case series have been published but there is no consensus about ideal treatment. We performed a systematic review, initially screening 775 titles, and included 12 papers comprising 91 patients with GCT of the small bones of the hands and feet. The rate of recurrence across these publications was found to be 72% (18 of 25) in those treated with isolated curettage, 13% (2 of 15) in those treated with curettage plus adjuvants, 15% (6 of 41) in those treated by resection and 10% (1 of 10) in those treated by amputation.

We then retrospectively analysed 30 patients treated for GCT of the small bones of the hands and feet between 1987 and 2010 in five specialised centres. The primary treatment was curettage in six, curettage with adjuvants (phenol or liquid nitrogen with or without polymethylmethacrylate (PMMA)) in 18 and resection in six. We evaluated the rate of complications and recurrence as well as the factors that influenced their functional outcome.

At a mean follow-up of 7.9 years (2 to 26) the rate of recurrence was 50% (n = 3) in those patients treated with isolated curettage, 22% (n = 4) in those treated with curettage plus adjuvants and 17% (n = 1) in those treated with resection (p = 0.404). The only complication was pain in one patient, which resolved after surgical removal of remnants of PMMA. We could not identify any individual factors associated with a higher rate of complications or recurrence. The mean post-operative Musculoskeletal Tumor Society scores were slightly higher after intra-lesional treatment including isolated curettage and curettage plus adjuvants (29 (20 to 30)) compared with resection (25 (15 to 30)) (p = 0.091). Repeated curettage with adjuvants eventually resulted in the cure for all patients and is therefore a reasonable treatment for both primary and recurrent GCT of the small bones of the hands and feet.

Cite this article: Bone Joint J 2013;95-B:838–45.

Objectives

The number of surgical procedures performed each year to treat femoroacetabular impingement (FAI) continues to rise. Although there is evidence that surgery can improve symptoms in the short-term, there is no evidence that it slows the development of osteoarthritis (OA). We performed a feasibility study to determine whether patient and surgeon opinion was permissive for a Randomised Controlled Trial (RCT) comparing operative with non-operative treatment for FAI.

Objectives

Lower limb muscle power is thought to influence outcome following total knee replacement (TKR). Post-operative deficits in muscle strength are commonly reported, although not explained. We hypothesised that post-operative recovery of lower limb muscle power would be influenced by the number of satellite cells in the quadriceps muscle at time of surgery.

The August 2012 Children’s orthopaedics Roundup³⁶⁰ looks at: whether 3D-CT gives a better idea of coverage than plain radiographs; forearm fractures after trampolining accidents; forearm fractures and the Rush pin; the fractured distal radius; elastic stable intramedullary nailing for long-bone fractures; aponeurotic recession for the equinus foot; the torn medial patellofemoral ligament and the adductor tubercle; slipped capital femoral epiphysis; paediatric wrist arthroscopy; and Pirani scores and clubfoot.

This study was designed to test the hypothesis that the sensory innervation of bone might play an important role in sensing and responding to low-intensity pulsed ultrasound and explain its effect in promoting fracture healing. In 112 rats a standardised mid-shaft tibial fracture was created, supported with an intramedullary needle and divided into four groups of 28. These either had a sciatic neurectomy or a patellar tendon resection as control, and received the ultrasound or not as a sham treatment. Fracture union, callus mineralisation and remodelling were assessed using plain radiography, peripheral quantitative computed tomography and histomorphology.

Daily ultrasound treatment significantly increased the rate of union and the volumetric bone mineral density in the fracture callus in the neurally intact rats (p = 0.025), but this stimulating effect was absent in the rats with sciatic neurectomy. Histomorphology demonstrated faster maturation of the callus in the group treated with ultrasound when compared with the control group. The results supported the hypothesis that intact innervation plays an important role in allowing low-intensity pulsed ultrasound to promote fracture healing.

Objectives

This study aimed to investigate time-dependent gene expression of injured human anterior cruciate ligament (ACL), and to evaluate the histological changes of the ACL remnant in terms of cellular characterisation.

Component malalignment can be associated with pain following total knee replacement (TKR). Using MRI, we reviewed 50 patients with painful TKRs and compared them with a group of 16 asymptomatic controls to determine the feasibility of using MRI in evaluating the rotational alignment of the components. Using the additional soft-tissue detail provided by this modality, we also evaluated the extent of synovitis within these two groups. Angular measurements were based on the femoral transepicondylar axis and tibial tubercle. Between two observers, there was very high interobserver agreement in the measurements of all values. Patients with painful TKRs demonstrated statistically significant relative internal rotation of the femoral component (p = 0.030). There was relative internal rotation of the tibial to femoral component and combined excessive internal rotation of the components in symptomatic knees, although these results were significant only with one of the observers (p = 0.031). There was a statistically significant association between the presence and severity of synovitis and painful TKR (p < 0.001).

MRI is an effective modality in evaluating component rotational alignment.

We evaluated the oncological and functional outcome of 18 patients, whose malignant bone tumours were excised with the assistance of navigation, and who were followed up for more than three years. There were 11 men and seven women, with a mean age of 31.8 years (10 to 57). There were ten operations on the pelvic ring and eight joint-preserving limb salvage procedures. The resection margins were free of tumour in all specimens. The tumours, which were stage IIB in all patients, included osteosarcoma, high-grade chondrosarcoma, Ewing’s sarcoma, malignant fibrous histiocytoma of bone, and adamantinoma. The overall three-year survival rate of the 18 patients was 88.9% (95% confidence interval (CI) 75.4 to 100). The three-year survival rate of the patients with pelvic malignancy was 80.0% (95% CI 55.3 to 100), and of the patients with metaphyseal malignancy was 100%. The event-free survival was 66.7% (95% CI 44.9 to 88.5). Local recurrence occurred in two patients, both of whom had a pelvic malignancy. The mean Musculoskeletal Tumor Society functional score was 26.9 points at a mean follow-up of 48.2 months (22 to 79).

We suggest that navigation can be helpful during surgery for musculoskeletal tumours; it can maximise the accuracy of resection and minimise the unnecessary sacrifice of normal tissue by providing precise intra-operative three-dimensional radiological information.

The purpose of this study was to investigate the development of the osseous acetabular index (OAI) and cartilaginous acetabular index (CAI) using MRI. The OAI and CAI were measured on the coronal MR images of the hip in 81 children with developmental dysplasia of the hip (DDH), with a mean age of 19.6 months (3 to 70), and 241 normal control children with a mean age of 5.1 years (1 month to 12.5 years). Additionally the developmental patterns of the OAI and CAI in normal children were determined by age-based cross-sectional analysis.

Unlike the OAI, the normal CAI decreased rapidly from a mean of 10.17° (sd 1.60) to a mean of 8.25° (sd 1.90) within the first two years of life, and then remained constant at a mean of 8.04° (sd 1.65) until adolescence. Although no difference in OAI was found between the uninvolved hips in children with unilateral DDH and normal hips (p = 0.639), the CAI was significantly different between them both (p < 0.001). The normal CAI has fully formed at birth, and is maintained constantly throughout childhood. The CAI in the unaffected hips in children with unilateral DDH is also mildly dysplastic.

The purpose of this study was to determine whether patients with a burst fracture of the thoracolumbar spine treated by short segment pedicle screw fixation fared better clinically and radiologically if the affected segment was fused at the same time. A total of 50 patients were enrolled in a prospective study and assigned to one of two groups. After the exclusion of three patients, there were 23 patients in the fusion group and 24 in the non-fusion group. Follow-up was at a mean of 23.9 months (18 to 30). Functional outcome was evaluated using the Greenough Low Back Outcome Score. Neurological function was graded using the American Spinal Injury Association Impairment Scale. Radiological outcome was assessed on the basis of the angle of kyphosis.

Peri-operative blood transfusion requirements and duration of surgery were significantly higher in the fusion group (p = 0.029 and p < 0.001, respectively). There were no clinical or radiological differences in outcome between the groups (all outcomes p > 0.05). The results of this study suggest that adjunctive fusion is unnecessary when managing patients with a burst fracture of the thoracolumbar spine with short segment pedicle screw fixation.

Objectives

Numerous complications following total knee replacement (TKR) relate to the patellofemoral (PF) joint, including pain and patellar maltracking, yet the options for in vivo imaging of the PF joint are limited, especially after TKR. We propose a novel sequential biplane radiological method that permits accurate tracking of the PF and tibiofemoral (TF) joints throughout the range of movement under weightbearing, and test it in knees pre- and post-arthroplasty.

The aim of this study was to determine the accuracy of registration and the precision of the resection volume in navigated hip arthroscopy for cam-type femoroacetabular impingement, using imageless and image-based registration. A virtual cam lesion was defined in 12 paired cadaver hips and randomly assigned to either imageless or image-based (three-dimensional (3D) fluoroscopy) navigated arthroscopic head–neck osteochondroplasty. The accuracy of patient–image registration for both protocols was evaluated and post-operative imaging was performed to evaluate the accuracy of the surgical resection. We found that the estimated accuracy of imageless registration in the arthroscopic setting was poor, with a mean error of 5.6 mm (standard deviation (sd) 4.08; 95% confidence interval (CI) 4.14 to 7.19). Because of the significant mismatch between the actual position of the probe during surgery and the position of that probe as displayed on the navigation platform screen, navigated femoral osteochondroplasty was physically impossible. The estimated accuracy of image-based registration by means of 3D fluoroscopy had a mean error of 0.8 mm (sd 0.51; 95% CI 0.56 to 0.94). In terms of the volume of bony resection, a mean of 17% (sd 11; -6% to 28%) more bone was resected than with the virtual plan (p = 0.02). The resection was a mean of 1 mm deeper (sd 0.7; -0.3 to 1.6) larger than on the original virtual plan (p = 0.02).

In conclusion, given the limited femoral surface that can be reached and digitised during arthroscopy of the hip, imageless registration is inaccurate and does not allow for reliable surgical navigation. However, image-based registration does acceptably allow for guided femoral osteochondroplasty in the arthroscopic management of femoroacetabular impingement.

Objectives

There remains a lack of data on the reliability of methods to estimate tibial coverage achieved during total knee replacement. In order to address this gap, the intra- and interobserver reliability of a three-dimensional (3D) digital templating method was assessed with one symmetric and one asymmetric prosthesis design.

Evaluation of patients with painful total knee replacement requires a thorough clinical examination and relevant investigations in order to reach a diagnosis. Awareness of the common and uncommon problems leading to painful total knee replacement is useful in the diagnostic approach. This review article aims to act as a guide to the evaluation of patients with painful total knee replacement.

Giant cell tumours (GCT) of the synovium and tendon sheath can be classified into two forms: localised (giant cell tumour of the tendon sheath, or nodular tenosynovitis) and diffuse (diffuse-type giant cell tumour or pigmented villonodular synovitis). The former principally affects the small joints. It presents as a solitary slow-growing tumour with a characteristic appearance on MRI and is treated by surgical excision. There is a significant risk of multiple recurrences with aggressive diffuse disease. A multidisciplinary approach with dedicated MRI, histological assessment and planned surgery with either adjuvant radiotherapy or systemic targeted therapy is required to improve outcomes in recurrent and refractory diffuse-type GCT.

Although arthroscopic synovectomy through several portals has been advocated as an alternative to arthrotomy, there is a significant risk of inadequate excision and recurrence, particularly in the posterior compartment of the knee. For local disease partial arthroscopic synovectomy may be sufficient, at the risk of recurrence. For both local and diffuse intra-articular disease open surgery is advised for recurrent disease. Marginal excision with focal disease will suffice, not dissimilar to the treatment of GCT of tendon sheath. For recurrent and extra-articular soft-tissue disease adjuvant therapy, including intra-articular radioactive colloid or moderate-dose external beam radiotherapy, should be considered.

We have measured the three-dimensional patterns of carpal deformity in 20 wrists in 20 rheumatoid patients in which the carpal bones were shifted ulnarwards on plain radiography. Three-dimensional bone models of the carpus and radius were created by computerised tomography with the wrist in the neutral position. The location of the centroids and rotational angle of each carpal bone relative to the radius were calculated and compared with those of ten normal wrists.

In the radiocarpal joint, the proximal row was flexed and the centroids of all carpal bones translocated in an ulnar, proximal and volar direction with loss of congruity. In the midcarpal joint, the distal row was extended and congruity generally well preserved. These findings may facilitate more positive use of radiocarpal fusion alone for the deformed rheumatoid wrist.

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.

Hip arthroscopy is particularly attractive in children as it confers advantages over arthrotomy or open surgery, such as shorter recovery time and earlier return to activity. Developments in surgical technique and arthroscopic instrumentation have enabled extension of arthroscopy of the hip to this age group. Potential challenges in paediatric and adolescent hip arthroscopy include variability in size, normal developmental change from childhood to adolescence, and conditions specific to children and adolescents and their various consequences. Treatable disorders include the sequelae of traumatic and sports-related hip joint injuries, Legg–Calve–Perthes’ disease and slipped capital femoral epiphysis, and the arthritic and septic hip. Intra-articular abnormalities are rarely isolated and are often associated with underlying morphological changes.

This review presents the current concepts of hip arthroscopy in the paediatric and adolescent patient, covering clinical assessment and investigation, indications and results of the experience to date, as well as technical challenges and future directions.