Flexion and extension laxity after medial, mobile-bearing unicompartmental knee arthroplasty: a comparison between a spacer- and a tension-guided technique.

PURPOSE: In a mobile-bearing unicompartmental knee arthroplasty (UKA), stability is of utmost importance to promote knee function and to prevent dislocation of the insert. Gap balancing can be guided by the use of spacers or a tensioner. The goal of this study is to compare laxity of a tension-guided implantation technique versus a spacer-guided technique for medial UKA with a mobile bearing. Also clinical function was compared between the groups. METHODS: The tension-guided UKA system (BalanSys™, Mathys Ltd, Bettlach, Switzerland) was compared with a retrospective group with a spacer-guided system (Oxford, Biomet Ltd, Bridgend, UK). A total of 30 tension-guided medial UKAs were implanted and compared with 35 spacer-guided medial prostheses. In both groups, valgus laxity was measured at least 4 months postoperatively in extension and 70° flexion using stress radiographs. Knee Society Scores (KSS) were obtained at the 6-month follow-up. RESULTS: Valgus laxity in flexion was significantly higher in the tension-guided group compared with the spacer-guided group: 3.9° (SD 1.8°) versus 2.4° (SD 1.2°), respectively, P < 0.001). In extension, valgus laxity was significantly different: 1.8° (SD 1.0°) in the tension-guided group compared with 2.7° (SD 0.9°) in the spacer-guided group (P < 0.001). There was no significant difference between the KSS for the two groups (n.s.). CONCLUSIONS: The tensor-guided system resulted in significantly more valgus laxity in flexion compared with the spacer-guided system. However, in extension, the situation was reversed: the tension-guided system resulted in less valgus laxity than the spacer-guided system. Clinically, there were no differences between the groups. The valgus laxity found with the spacer-guided system better approximates the valgus laxity values of the healthy elderly.

Functional performance of mobile versus fixed bearing total knee prostheses: a randomised controlled trial.

PURPOSE: The primary goal of this study was to assess the difference in active flexion between patients with a mobile versus a fixed bearing, cruciate retaining, and total knee arthroplasty. The study was designed as a randomised controlled multi-centre trial. METHODS: Participants were assigned to interventions by using block-stratified, random allocation. Outcome parameters were active flexion, passive flexion, and Knee Society Score (KSS). Outcome parameters were assessed preoperatively and at 3, 6, and 12 months postoperatively by an independent nurse. RESULTS: Ninety-two patients from one centre were included, 46 in each group. Active flexion was comparable for the two groups, 99.9° for the mobile bearing group and 101° for the fixed bearing group with a baseline controlled difference of 1.0 (95% CI -3.9 to 5.8, n.s.). The Clinical KSS was comparable between the two bearing groups (Mobile 90.0 vs. fixed 92.4, n.s.). The functional KSS showed a difference that was attributable to the stair climbing subscore, which showed a difference in favour of the fixed bearing design between preoperative and 3 months (7.3 point difference; 95% CI 2.3-12.5; P = 0.005) as well as 12 months (4.8 point difference; 95% CI 0.1-9.6; P = 0.045). CONCLUSIONS: There were no short-term differences in active flexion between fixed bearing and mobile bearing total knee arthroplasty. LEVEL OF EVIDENCE: I.

Evaluating hand surgery in patients with rheumatoid arthritis: short-term effect on dexterity and pain and its relationship with patient satisfaction.

Short-term effect of hand surgery on hand function in activities of daily life (dexterity) and pain were studied in 70 patients with rheumatoid arthritis. Only surgical interventions aimed at improvement of function and/or pain relief were included in the study. Patients were assessed before surgery and 6 and 12 months after surgery. Clinical change in the surgical group was observed in the number of painful and swollen joints, observed dexterity, and pain in the hand. Six months after surgery 74% of the patients showed positive clinical change in hand functioning and/or hand pain. Clinical effects remained stable between 6 and 12 months after surgical assessments. Both change in observed dexterity and pain had an independent impact on the patient's satisfaction with the results of the surgery.

Osteonecrosis after treatment for heterotopic ossification in spinal cord injury with the combination of surgery, irradiation, and an NSAID.

STUDY DESIGN: Case report. OBJECTIVE: Heterotopic ossification (HO) is a frequent complication in spinal cord injury (SCI) that is often difficult to treat. Although surgery may become necessary, operative resection has been associated with complications and poor outcome due to a high recurrence rate. Additional methods of treatment to reduce the recurrence rate have been developed, including post operative irradiation and NSAIDs. This article presents three patients, who developed an osteonecrosis of the femoral head after the combined treatment for HO of surgery, irradiation, and an NSAID.

Double-blind, placebo-controlled study of the effects of tibolone on bone mineral density in postmenopausal osteoporotic women with and without previous fractures.

A 2-year placebo-controlled, randomized, two-center prospective study was carried out to assess the effects of tibolone (Org OD14, Livial) on trabecular and cortical bone mass and bone biochemistry parameters in elderly postmenopausal women with and without previous fractures. In total, 107 subjects, 71 with fractures and 36 without fractures, were randomized to tibolone (n = 64) or placebo (n = 43). Their mean age was 63.1 years. Bone mineral density (BMD) (g/cm2) was assessed at baseline and every 6 months for 2 years by dual-energy X-ray absorptiometry (DXA). Mean baseline values were 0.79 and 0.80 for the lumbar spine in the tibolone and placebo groups, respectively, and for the femoral neck 0.64 in both groups. Serum and urinary bone biochemistry parameters were measured concurrently. An analysis of variance (ANOVA) model including center and group was applied. The completers' group was the primary subset for the analysis; the intention-to-treat (ITT) group was also analyzed. Results are expressed as the percentage change at 24 months and the annual rate of change percentage year. The tibolone group showed an overall mean increase (vs. placebo) in BMD at the lumbar spine of 7.2% (p < 0.001) and for the femoral neck 2.6% (p < 0.001). In subjects with previous fractures increases were 6.0% and 4.0% for the lumbar spine and femoral neck, while in those with no fractures, respective changes were 8.9% and 1.1%. Overall changes in the placebo group were 0.9% and -1.6% for the lumbar spine and femoral neck, respectively. A significant fall in bone biochemistry parameters showed that tibolone inhibits osteoclastic activity. In conclusion we have found that tibolone 2.5 mg induces significant increases of trabecular and cortical bone mass in elderly postmenopausal osteoporotic women with and without previous fractures.

Temporary external transpedicular fixation of the lumbosacral spine.

STUDY DESIGN: In this study, 133 patients with incapacitating low back pain underwent temporary external transpedicular fixation of the lumbosacral spine in a prospective trial. Of these patients, 67% had undergone one or more spinal procedures in the past. On the basis of temporary external transpedicular fixation, 55 of 133 patients were treated conservatively. With an average follow-up period of 37 months, the clinical results were analyzed. OBJECTIVE: To evaluate temporary external transpedicular fixation as a test for selecting suitable candidates for fusion of the lumbosacral spine. SUMMARY OF BACKGROUND DATA: The few reports regarding this test are contradictory in terms of predictive value and morbidity. Only three reports include a placebo trial. METHODS: All patients were tested with the external fixator in three different positions: neutral fixation, slight distraction, and nonfixation (bars disconnected). The patient was unaware of the exact position of the external fixator and thus served as his or her own control. Before and during the test and at follow-up examination, pain was assessed on a visual analog scale. RESULTS: In the group that eventually underwent spinal fusion, the average preoperation visual analog scale score was 77. During test fixation, the average score was 26, in nonfixation 69, and at follow-up after surgery 40. In the control group, these figures were 75, 53, 44, and 71, respectively. As statistical analysis showed, the only factors that could be associated with the improved pain score was the performance of the spinal fusion (P = 0.0001) and the duration of low back pain before the test (P = 0.04). CONCLUSION: In selecting suitable candidates for spinal fusion, temporary external transpedicular fixation (including a placebo trial) can be a valuable test.

The effect of a plaster cast on lumbosacral joint motion. An in vivo assessment with precision motion analysis system.

STUDY DESIGN: This study was conducted to assess the effect of a plaster cast on the mobility of the lumbosacral joint in 10 patients with chronic low back pain. During static and dynamic exercises, movements between the proximal vertebra (L4 or L5) and the sacrum were registered in 10 patients without a support and after the application of a plaster cast, and with and without unilateral hip immobilization, respectively. OBJECTIVES: To investigate whether plaster casts actually immobilize the lumbosacral joint. SUMMARY OF BACKGROUND DATA: The presumed stabilizing effect of a lumbar orthosis on the lumbosacral joint has been the subject of many studies in the past years, and contradictory reports have been published. METHODS: The measurements were performed by means of Precision Motion Analysis System, an optoelectronic three-dimensional motion analysis system using infrared light. The patients were asked to perform maximal spinal flexion to extension, maximal pelvic tilt (static test conditions), and to walk within the measurement volume (dynamic test condition). This procedure was repeated with the patients wearing a plaster cast with and without unilateral hip fixation. Mobility was expressed in translations and rotations around three axes. For statistical analysis, repeated measurements two-way analysis of variance was used. RESULTS: Considerable rotations were found only in the sagittal plane. Both plaster casts appeared to decrease mobility during the static test conditions. During the dynamic test condition, however, no significant decrease of mobility of the lumbosacral joint by either of the casts could be observed. In both cast conditions, considerably more sagittal rotation was found during walking than with the other two exercises. CONCLUSION: In the sagittal plane, a plaster cast with or without unilateral hip immobilization can decrease motion during spinal flexion-extension. This stabilizing effect on the lumbosacral joint could not be observed during walking.

Stanmore total hip replacement. A nine- to ten-year follow-up.

Between February 1975 and August 1976, 195 total hip replacements using Stanmore components were performed; of these, 146 were in 135 patients who had not had previous hip surgery. At review 52 had died, but none of the others was lost to follow-up. Of the 52, two had had a second operation, one for infection and one for recurrent dislocation. In the remaining 83 patients (92 hips) five revisions were necessary: four for aseptic loosening, and one for stem fracture. The remaining 78 patients had little or no pain and little restriction of activity. After a follow-up period of at least nine years, the survival rate of the prosthesis was 95%. There had been migration of the femoral component in five cases and migration of the acetabular cup in one case, but no wear of the acetabular component could be demonstrated.

Treatment of femoral neck fractures by hemiarthroplasty.

Seventy-five patients with a displaced unstable fracture of the femoral neck were reviewed to evaluate treatment by cemented hemiarthroplasty through a posterior approach. Twenty-three patients were available for follow-up. The mean duration of follow-up was 46.7 months. Twenty-one patients (91%) showed a good clinical result. Sixteen patients (69%) had maintained their preoperative mobility or had deteriorated slightly. Major complications were divided as follows: mortality: six patients (6/75, 8%); early deep infection (3/23.4%) and dislocation (5/23, 7%). In four patients (4/23, 5%) a revision operation was required. Radiological evaluation showed possible loosening in one patient. Protrusion was not observed.