The June 2014 Wrist & Hand Roundup360 looks at: aart throwing not quite as we thought; two-gear, four-bar linkage in the wrist?; assessing outcomes in distal radial fractures; gold standard Swanson’s?; multistrand repairs of unclear benefit in flexor tendon release; for goodness’ sake, leave the thumb alone in scaphoid fractures; horizons in carpal tunnel surgery; treading the Essex-Lopresti tightrope; wrist replacement in trauma? and radial shortening reliable in the long term for Kienbock’s disease

Objectives

Although many clinical and experimental investigations have shed light on muscle atrophy and intramuscular accumulation of fat after rotator cuff disruption, none have reported on their onset in the absence of muscle retraction.

We prospectively followed 171 patients who underwent bilateral unicompartmental knee replacement (UKR) over a period of two years. Of these, 124 (72.5%) underwent a simultaneous bilateral procedure and 47 (27.5%) underwent a staged procedure. The mean cumulative operating time and length of hospital stay were both shorter in the simultaneous group, by 22.5 minutes (p < 0.001) and three days (p < 0.001), respectively. The mean reduction in haemoglobin level post-operatively was greater by 0.15 g/dl in the simultaneous group (p = 0.023), but this did not translate into a significant increase in the number of patients requiring blood transfusion (p = 1.000). The mean hospital cost was lower by $8892 in the simultaneous group (p < 0.001). There was no significant difference in the rate of complications between the groups, and at two-year follow-up there was no difference in the outcomes between the two groups.

We conclude that simultaneous bilateral UKR can be recommended as an appropriate treatment for patients with bilateral medial compartment osteoarthritis of the knee.

Cite this article: Bone Joint J 2013;95-B:788–92.

The August 2012 Trauma Roundup³⁶⁰ looks at: pelvic fractures, thromboembolism and the Japanese; venous thromboembolism risk after pelvic and acetabular fractures; the displaced clavicular fracture; whether to use a nail or plate for the displaced fracture of the distal tibia; the dangers of snowboarding; how to predict the outcome of lower leg blast injuries; compressive external fixation for the displaced patellar fracture; broken hips in Morocco; and spinal trauma in mainland China.

Elastic stable intramedullary nailing (ESIN) is generally acknowledged to be the treatment of choice for displaced diaphyseal femoral fractures in children over the age of three years, although complication rates of up to 50% are described. Pre-bending the nails is recommended, but there are no published data to support this. Using synthetic bones and a standardised simulated fracture, we performed biomechanical testing to determine the influence on the stability of the fracture of pre-bending the nails before implantation. Standard ESIN was performed on 24 synthetic femoral models with a spiral fracture. In eight cases the nails were inserted without any pre-bending, in a further eight cases they were pre-bent to 30° and in the last group of eight cases they were pre-bent to 60°. Mechanical testing revealed that pre-bending to 60° produced a significant increase in the stiffness or stability of the fracture. Pre-bending to 60° showed a significant positive influence on the stiffness compared with unbent nails. Pre-bending to 30° improved stiffness only slightly.

These findings validate the recommendations for pre-bending, but the degree of pre-bend should exceed 30°. Adopting higher degrees of pre-bending should improve stability in spiral fractures and reduce the complications of varus deformity and shortening.

The technical advances in arthroscopic surgery of the hip, including the improved ability to manage the capsule and gain extensile exposure, have been paralleled by a growth in the number of conditions that can be addressed. This expanding list includes symptomatic labral tears, chondral lesions, injuries of the ligamentum teres, femoroacetabular impingement (FAI), capsular laxity and instability, and various extra-articular disorders, including snapping hip syndromes. With a careful diagnostic evaluation and technical execution of well-indicated procedures, arthroscopic surgery of the hip can achieve successful clinical outcomes, with predictable improvements in function and pre-injury levels of physical activity for many patients.

This paper reviews the current position in relation to the use of arthroscopy in the treatment of disorders of the hip.

Cite this article: Bone Joint J 2013;95-B:10–19.

The aim of this study was to compare the results in patients having a quadriceps sparing total knee replacement (TKR) with those undergoing a standard TKR at a minimum follow-up of two years.

All patients who had a TKR with a high-flex posterior-stabilised prosthesis prior to December 2002 were reviewed retrospectively. There were 57 patients available for follow-up. Those with a quadriceps sparing TKR had less pain peri-operatively with a greater degree of flexion at all the post-operative visits and at the final follow-up, but their operations took longer, with less accurate radiological alignment. There was no difference in the complications and in the Knee Society scores between the two groups at the final follow-up.

Total knee replacement through a quadriceps sparing approach has some peri-operative advantages over the standard incision. At a minimum follow-up of two years the clinical results were similar to those with a standard incision, but the radiological outcomes of the quadriceps sparing group were inferior.

We describe 261 peripheral nerve injuries sustained in war by 100 consecutive service men and women injured in Iraq and Afghanistan. Their mean age was 26.5 years (18.1 to 42.6), the median interval between injury and first review was 4.2 months (mean 8.4 months (0.36 to 48.49)) and median follow-up was 28.4 months (mean 20.5 months (1.3 to 64.2)). The nerve lesions were predominantly focal prolonged conduction block/neurapraxia in 116 (45%), axonotmesis in 92 (35%) and neurotmesis in 53 (20%) and were evenly distributed between the upper and the lower limbs. Explosions accounted for 164 (63%): 213 (82%) nerve injuries were associated with open wounds. Two or more main nerves were injured in 70 patients. The ulnar, common peroneal and tibial nerves were most commonly injured. In 69 patients there was a vascular injury, fracture, or both at the level of the nerve lesion. Major tissue loss was present in 50 patients: amputation of at least one limb was needed in 18. A total of 36 patients continued in severe neuropathic pain.

This paper outlines the methods used in the assessment of these injuries and provides information about the depth and distribution of the nerve lesions, their associated injuries and neuropathic pain syndromes.

We have reviewed 38 surgically treated cases of spontaneous posterior interosseous nerve palsy in 38 patients with a mean age of 43 years (13 to 68) in order to identify clinical factors associated with its prognosis. Interfascicular neurolysis was performed at a mean of 13 months (1 to 187) after the onset of symptoms. The mean follow-up was 21 months (5.5 to 221). Medical Research Council muscle power of more than grade 4 was considered to be a good result. A further 12 cases in ten patients were treated conservatively and assessed similarly.

Of the 30 cases treated surgically with available outcome data, the result of interfascicular neurolysis was significantly better in patients < 50 years old (younger group (18 nerves); good: 13 nerves (72%), poor: five nerves (28%)) than in cases > 50 years old (older group (12 nerves); good: one nerve (8%), poor: 11 nerves (92%)) (p < 0.001). A pre-operative period of less than seven months was also associated with a good result in the younger group (p = 0.01). The older group had a poor result regardless of the pre-operative delay.

Our recommended therapeutic approach therefore is to perform interfascicular neurolysis if the patient is < 50 years of age, and the pre-operative delay is < seven months. If the patient is > 50 years of age with no sign of recovery for seven months, or in the younger group with a pre-operative delay of more than a year, we advise interfascicular neurolysis together with tendon transfer as the primary surgical procedure.

Between May 1998 and May 2007 we carried out 50 Avon patellofemoral joint replacements in 32 patients with isolated patellofemoral osteoarthritis.

There were no revisions in the first five years, giving a cumulative survival of 100% for those with a minimum follow-up of five years. The mean follow-up was 5.3 years (2.1 to 10.2). The median Oxford knee score was 30.5 (interquartile range 22.25 to 42.25). In patients with bilateral replacements the median Euroqol General health score was 50 which was significantly lower than that of 75 in those with a unilateral replacement (p = 0.047). The main complication was progression of disease, which was identified radiologically in 11 knees (22%). This highlights the need for accurate selection of patients. Our findings suggest that the Avon prosthesis survives well and gives a satisfactory functional outcome in the medium term.

Between 1989 and 1992 we had 102 knees suitable for unicompartmental knee replacement (UKR). They were randomised to receive either a St Georg Sled UKR or a Kinematic modular total knee replacement (TKR). The early results demonstrated that the UKR group had less complications and more rapid rehabilitation than the TKR group. At five years there were an equal number of failures in the two groups but the UKR group had more excellent results and a greater range of movement.

The cases were reviewed by a research nurse at 8, 10 and 12 years after operation. We report the outcome at 15 years follow-up. A total of 43 patients (45 knees) died with their prosthetic knees intact. Throughout the review period the Bristol knee scores of the UKR group have been better and at 15 years 15 (71.4%) of the surviving UKRs and 10 (52.6%) of the surviving TKRs had achieved an excellent score. The 15 years survivorship rate based on revision or failure for any reason was 24 (89.8%) for UKR and 19 (78.7%) for TKR. During the 15 years of the review four UKRs and six TKRs failed.

The better early results with UKR are maintained at 15 years with no greater failure rate. The median Bristol knee score of the UKR group was 91.1 at five years and 92 at 15 years, suggesting little functional deterioration in either the prosthesis or the remainder of the joint. These results justify the increased use of UKR.

Muscle atrophy has been demonstrated in patients suffering from osteoarthritis of the hip, but little is known about muscular recovery after total hip replacement (THR). A total of 20 patients with unilateral osteoarthritis of the hip were assessed before, six months and two years after THR. The cross-sectional area and radiological density of the muscles of the hip, thigh, calf and back were measured using CT. We hypothesised that the muscles would not recover fully after operation.

After two years comparison of the limb with the THR with the healthy limb showed that there was such a reduction in the cross-sectional area in iliopsoas (7.0%; p = 0.006) and the hip adductors (8.4%, p = 0.003) and in the radiological density in gluteus maximus (10.1 Hounsfield units; p < 0.001), gluteus medius/minimus (5.6 Hounsfield units; p = 0.011), iliopsoas (3.9 Hounsfield units; p < 0.001) and the adductors (2.4 Hounsfield units; p = 0.022).

Thus, there was persistent muscle atrophy in muscles acting about the hip two years after THR. We suggest that an earlier operation or a more intensive rehabilitation may reverse these changes.

We have reviewed 42 patients who had revision of metal-on-metal resurfacing procedures, mostly because of problems with the acetabular component. The revisions were carried out a mean of 26.2 months (1 to 76) after the initial operation and most of the patients (30) were female.

Malpositioning of the acetabular component resulted in 27 revisions, mostly because of excessive abduction (mean 69.9°; 56° to 98°) or insufficient or excessive anteversion. Seven patients had more than one reason for revision. The mean increase in the diameter of the component was 1.8 mm (0 to 4) when exchange was needed.

Malpositioning of the components was associated with metallosis and a high level of serum ions. The results of revision of the femoral component to a component with a modular head were excellent, but four patients had dislocation after revision and four required a further revision.

We present a case of disruption of the posterolateral corner of the knee with avulsion of the tendon of biceps femoris. Repair and reconstruction included an allogenic tendon graft to replace the posterior cruciate ligament. Surgery was followed by a complete common peroneal nerve palsy. Revision surgery revealed that the nerve had been displaced anteriorly by avulsion of the biceps tendon and the tendon graft encircled it. Release of the nerve restored normal function at five months.

We carried out an audit on the result of achieving early walking in total knee replacement after instituting a new rehabilitation protocol, and assessed its influence on the development of deep-vein thrombosis as determined by Doppler ultrasound scanning on the fifth post-operative day. Early mobilisation was defined as beginning to walk less than 24 hours after knee replacement.

Between April 1997 and July 2002, 98 patients underwent a total of 125 total knee replacements. They began walking on the second post-operative day unless there was a medical contraindication. They formed a retrospective control group. A protocol which allowed patients to start walking at less than 24 hours after surgery was instituted in August 2002. Between August 2002 and November 2004, 97 patients underwent a total of 122 total knee replacements. They formed the early mobilisation group, in which data were prospectively gathered. The two groups were of similar age, gender and had similar medical comorbidities. The surgical technique and tourniquet times were similar and the same instrumentation was used in nearly all cases. All the patients received low-molecular-weight heparin thromboprophylaxis and wore compression stockings post-operatively.

In the early mobilisation group 90 patients (92.8%) began walking successfully within 24 hours of their operation. The incidence of deep-vein thrombosis fell from 27.6% in the control group to 1.0% in the early mobilisation group (chi-squared test, p < 0.001). There was a difference in the incidence of risk factors for deep-vein thrombosis between the two groups. However, multiple logistic regression analysis showed that the institution of an early mobilisation protocol resulted in a 30-fold reduction in the risk of post-operative deep-vein thrombosis when we adjusted for other risk factors.

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.