Late operative site pain with isola posterior instrumentation requiring implant removal: infection or metal reaction?

OBJECTIVES: To elucidate the cause of late operative site pain in six cases of scoliosis managed with Isola posterior instrumentation that required removal of the implants. METHOD: Microbiologic examination of wound swabs and enriched culture of operative tissue specimens was undertaken in all cases. Histologic study of the peri-implant membranes also was conducted. RESULTS: The presentation in all cases was similar: back pain appearing between 12-20 months after surgery, followed by a local wound swelling leading to a wound sinus. In only one of these cases was the discharge positive for bacterial growth. Implant removal was curative. Histologic examination of tissue specimens revealed a neutrophil-rich granulation tissue reaction suggestive of an infective etiology despite the failure to isolate organisms. Within the granulation tissue was metallic debris that varied from very sparse to abundant from fretting at the distal cross-connector junctions. A review of recent literature describing similar problems suggests that late onset spinal pain is a real entity and a major cause of implant removal. CONCLUSIONS: On reviewing the evidence for an infective etiology versus a metallurgic reaction etiology for these cases of late onset spinal pain, it was concluded that a subacute low-grade implant infection was the main cause. Histologic findings would seem to confirm low-grade infection. There may be more than one causative factor for late operative site pain, as it is possible that fretting at cross connection junctions may provide the environment for the incubation of dormant or inactive microbes.

Syme's amputation revisited: a review of 46 cases.

We assessed 46 Syme's amputees attending our prosthetic clinics in terms of the clinical and radiological condition of their stumps, their level of function and problems with the prosthesis. Twenty-five were compared with a matching group of 25 transtibial amputees in regard to activity, function and prosthetic behaviour. Function was similar in the two groups, but Syme's amputees had a higher incidence of prosthetic failure. Overall, Syme's amputees were pleased with their prostheses and their function. Childhood amputations were associated with fewer long-term problems in terms of function and stump problems. Syme's amputation is indicated for congenital foot deformities, fibular hemimelia and severe injury to the foot as long as the heel pad remains viable.

Progression of scoliosis after spinal fusion in Duchenne's muscular dystrophy.

A consecutive series of 85 patients with Duchenne's muscular dystrophy who underwent spinal fusion over a period of 16 years was followed up with regard to the progression of the scoliosis and pelvic obliquity. Of 74 patients with adequate radiographic follow-up, 55 were instrumented with the Luque single-unit rod system and 19 with the Isola pedicle screw system; seven were instrumented to L3/4, 42 to L5, 15 to S1 and 10 to the pelvis with intrailiac rods. The mean period of follow-up was 49 months (SD 22) before and 47 months (SD 24) after operation. There was one peri-operative death and three cases of failure of hardware. The mean improvement in the Cobb angle was 26 degrees and in pelvic obliquity, 9.2 degrees. Fusion to L3/4 achieved a poorer correction of both curves while intrapelvic rods, achieved and maintained the best correction of pelvic obliquity. Fusion to S1 did not provide any benefit over more proximal fusion excluding the sacrum, with regard to correction and maintenance of both angles. The Isola system appeared to provide and maintain a slightly better correction of the Cobb angle.

Wound infection in hip and knee arthroplasty.

We have studied prospectively the outcome of wound discharge in patients after arthroplasty of the hip and knee. Over a period of 3.5 years 530 primary arthroplasties were carried out in one hospital. Postoperative wound infections developed in 82. At a mean follow-up of two years a comparison was made between these patients and 82 with healthy wounds, in terms of symptoms and signs of deep infection. There was an incidence of 1.1% of early deep infection, within six weeks in all cases. The rate of 'superficial' infection was 17.3% in the hips, 10.5% in the knees and 14.3% in total. At a mean follow-up of 26 months, there were no significant differences between the patients with infected wounds and a matched group of patients with healthy wounds in terms of the ESR, level of C-reactive protein, white cell count and radiological scores, but clinical scores were significantly worse in the patients with infected knees (p < 0.05). The length of stay was also significantly longer in this group (mean 14.6 days in the healthy wound group, 19 days in the problem group; p < 0.005). There was, however, no convincing evidence that these wound infections led to deep infection and early revision in the early to medium follow-up period. A larger and longer prospective trial would be necessary to shed more light on this potential problem.

Upper limb traumatic amputees. Review of prosthetic use.

The prosthetic status of the traumatic upper limb amputees was reviewed. Fifty-five upper limb amputees were reviewed using a detailed questionnaire, telephone or clinic review and by case note study. Twenty-three patients were traumatic amputees and 32 were congenital amputees. The amputees' function, prosthetic use and satisfaction were evaluated and this formed the basis of a scoring system. The traumatic group were less satisfied with their prosthesis and their functional ability was poorer, especially in the use of the myoelectric prosthesis. Traumatic amputees were their prosthesis for an average of 6.5 hours per day compared to 9.3 hours in the atraumatic group. None of the traumatic amputees fitted after 12 weeks returned to gainful employment. Early prosthetic fitting, rehabilitation and post-traumatic counselling are advocated in upper limb traumatic amputees in order to achieve an optimum prosthetic benefit for the patient.

Postoperative blood loss into plaster casts after clubfoot surgery: an experimental model.

With major surgery in mind, a simple experimental model was used to study the potential blood loss into plaster of Paris casts. Three lower limb models were used to represent a 3-year-old, a 1-year-old, and a 6-month-old. Two thicknesses of plaster were compared in terms of blood volume required to produce staining on the surface of the cast. Whole blood from the laboratory was infused onto the plaster models at various rates. While allowing for the limitations of the model, the blood volume required before staining through the plaster when three plaster rolls were used was an average of 160 mL in the 6-month-old model and 310 mL in the 3-year-old modal, representing 31.4% and 29.5% of total blood volume, respectively. When only two rolls of plaster of Paris were used, an average of 80 mL in the 6-month-old and 180 mL in the 3-year-old model were lost, representing 15.7% and 17% of total blood volume, respectively. This potential blood loss should be borne in mind during major pediatric foot surgery. The use of drains, releasing the tourniquet before wound closure, and casting with two rather than three rolls of plaster are suggested precautions.

Chronic low back pain in traumatic lower limb amputees.

OBJECTIVE: To ascertain the prevalence of back pain amongst traumatic lower limb amputees attending a regional rehabilitation centre and to determine the possible causes of back pain. DESIGN: All traumatic lower limb amputees given a semi-structured questionnaire to complete and a comparative subgroup of amputees with back pain and without back pain underwent physical examination, gait analysis, magnetic resonance scanning (MRI) and gait/standing stability analysis. SETTING: A subregional amputee rehabilitation centre. RESULTS: Transfemoral amputees were more likely to suffer from back pain (81 %) than transtibial amputees (62%) (p<0.05) and of those suffering from severe back pain, 89% and 81% also suffered from severe pain in the phantom limb and severe stump pain respectively. In two comparative subgroups of amputees there was no significant difference between back pain and pain-free groups except those with pain were more likely to have a body mass index (BMI) ratio above 50% of the recommended ratio. No difference in degeneration or disc disease between the groups on MR scans was found. Impact ground reaction forces during walking, irrespective of limb, were significantly greater (p < 0.05) in the pain-free group than in the pain group, as was walking speed. Gait asymmetry measures were similar in both groups. Centre of pressure displacement measures during standing were greater in the pain group than in the pain-free group. CONCLUSIONS: Low back pain in amputees is a significant problem equal to that of pain in the phantom limb and a biomechanical (myofascial) rather than a degenerative aetiology is suggested.

Hand problems presenting to a district general hospital accident and emergency department.

An audit was carried out of 1000 consecutive patients presenting with hand problems to a busy district general hospital (DGH), accident and emergency department (A&E). Hand problems accounted for 11% of all A&E presentations. Over 50% of cases were examined radiologically with 37% of these having positive findings. Most patients were male (66%) and manual workers (34%). Only 2.8% of patients required admission, and 50% were discharged with no follow-up. Less than 5% were referred by their general practitioner (GP) and these patients presented during office hours (08.00-18.00 h). The vast majority of the presenting patients could have been treated in a modern, well equipped GP surgery.

The Charnley-Hastings bipolar prosthesis in femoral neck fractures - a study of dynamic motion.

Fourteen patients who had a Charnley-Hastings bipolar prosthesis inserted for a fracture of the neck of the femur underwent a fluoroscopic assessment of the prosthesis while walking on a treadmill at an average of 24 months (range 8-48 months) post-insertion. This motion was compared with static weight-bearing and non-weight-bearing motion. The area of interest was the motion at the interprosthetic junction. Previous studies of this and similar prostheses had suggested that interprosthetic motion lessened with time, as the inner bearing stiffened up. However, in this study it was found that although the interprosthetic motion during non-weight-bearing abduction was in the region of 20-30% of total abduction, the interprosthetic motion during flexion and extension in gait accounted for 70-80% of motion. We suggest this can be explained by considering the biomechanical effect of sliding friction at the metal-acetabular bone junction during weight-bearing gait, as well as the impingement of the neck on the prosthetic socket during extremes of movement. The reported superior long term results of the bipolar prosthesis over its unipolar counterparts in femoral neck fracture treatment can be explained by the delayed acetabular wear due to reduced motion, and shear forces, at the prosthetic-bone interface.

Early active mobilisation of volar plate avulsion fractures.

This is a prospective follow up of 190 consecutive cases of volar plate avulsion fractures. A standard management regimen of immediate, active movement was followed in all cases and physiotherapy was rarely required. Of the 190 patients, 162 were followed up for at least one year. An excellent or good outcome was achieved in 98 per cent. Patients presenting more than three weeks from injury had a worse outcome. The size and displacement of the avulsed fragment did not affect the outcome. For the stable joint, early active mobilisation with minimal or no splintage provides a good result.