David Beverland

A Minimal-incision Technique in Total Hip Arthroplasty Does Not Improve Early Postoperative Outcomes: A Prospective, Randomized, Controlled Trial

BACKGROUND Minimally invasive total hip arthroplasty has stirred substantial controversy with regard to whether it provides superior outcomes compared with total hip arthroplasty performed through longer incisions. The orthopaedic literature is deficient in well-designed scientific studies to support the clinical superiority of this approach. The objective of this study was to compare the results of a single mini-incision approach with those of a standard-incision total hip arthroplasty in the early postoperative period. METHODS Two hundred and nineteen patients (219 hips) admitted for unilateral total hip arthroplasty between December 2003 and June 2004 were randomized to undergo surgery through a short incision of <or=10 cm or a standard incision of 16 cm. All patients were blinded to the size of the incision for the duration of the hospital stay. The anesthetic, analgesic, and postoperative physiotherapy protocols were standardized, with the staff also blinded to the technique used. A single surgeon, who had performed more than 300 short-incision hip replacements prior to the start of this study and who performs an average of 415 primary total hip replacements a year, performed all procedures through a single-incision posterior approach using a cementless cup and cemented stem. RESULTS The two groups were matched for age, grade according to the system of the American Society of Anesthesiologists, and body mass index. No significant difference was detected with respect to postoperative hematocrit, blood transfusion requirements, pain scores, or analgesic use. We found no difference in early walking ability or length of hospital stay and no difference in component placement, cement-mantle quality, or functional outcome scores at six weeks. The patient variables significantly associated with a probability of early discharge independent of incision length were patient age and preoperative hemoglobin levels (p < 0.05). The surgical scars contracted significantly over six weeks (p < 0.05) but by a similar proportion of 11% to 12% in both groups. CONCLUSIONS Minimally invasive total hip arthroplasty performed through a single-incision posterior approach by a high-volume hip surgeon with extensive experience in less invasive approaches to the hip is safe and reproducible. However, it offers no significant benefit in the early postoperative period compared with a standard incision of 16 cm. As it is not known whether lower-volume and less-experienced surgeons can achieve similar results, the mini-incision technique merits further study before wide dissemination and implementation of this family of surgical approaches can be recommended.

Comparison of topical fibrin spray and tranexamic acid on blood loss after total knee replacement: A PROSPECTIVE, RANDOMISED CONTROLLED TRIAL

We performed a randomised, controlled trial involving 150 patients with a pre-operative level of haemoglobin of 13.0 g/dl or less, to compare the effect of either topical fibrin spray or intravenous tranexamic acid on blood loss after total knee replacement. A total of 50 patients in the topical fibrin spray group had 10 ml of the reconstituted product applied intra-operatively to the operation site. The 50 patients in the tranexamic acid group received 500 mg of tranexamic acid intravenously five minutes before deflation of the tourniquet and a repeat dose three hours later, and a control group of 50 patients received no pharmacological intervention. There was a significant reduction in the total calculated blood loss for those in the topical fibrin spray group (p = 0.016) and tranexamic acid group (p = 0.041) compared with the control group, with mean losses of 1190 ml (708 to 2067), 1225 ml (580 to 2027), and 1415 ml (801 to 2319), respectively. The reduction in blood loss in the topical fibrin spray group was not significantly different from that achieved in the tranexamic acid group (p = 0.72).

The transverse acetabular ligament: an aid to orientation of the acetabular component during primary total hip replacement: A PRELIMINARY STUDY OF 1000 CASES INVESTIGATING POSTOPERATIVE STABILITY

Ensuring the accuracy of the intra-operative orientation of the acetabular component during a total hip replacement can be difficult. In this paper we introduce a reproducible technique using the transverse acetabular ligament to determine the anteversion of the acetabular component. We have found that this ligament can be identified in virtually every hip undergoing primary surgery. We describe an intra-operative grading system for the appearance of the ligament. This technique has been used in 1000 consecutive cases. During a minimum follow-up of eight months the dislocation rate was 0.6%. This confirms our hypothesis that the transverse acetabular ligament can be used to determine the position of the acetabular component. The method has been used in both conventional and minimally-invasive approaches.

The influence of posterior condylar offset on knee flexion after total knee replacement using a cruciate-sacrificing mobile-bearing implant

We have studied the concept of posterior condylar offset and the importance of its restoration on the maximum range of knee flexion after posterior-cruciate-ligament-retaining total knee replacement (TKR). We measured the difference in the posterior condylar offset before and one year after operation in 69 patients who had undergone a primary cruciate-sacrificing mobile bearing TKR by one surgeon using the same implant and a standardised operating technique. In all the patients true pre- and post-operative lateral radiographs had been taken. The mean pre- and post-operative posterior condylar offset was 25.9 mm (21 to 35) and 26.9 mm (21 to 34), respectively. The mean difference in posterior condylar offset was + 1 mm (-6 to +5). The mean pre-operative knee flexion was 111 degrees (62 degrees to 146 degrees) and at one year postoperatively, it was 107 degrees (51 degrees to 137 degrees). There was no statistical correlation between the change in knee flexion and the difference in the posterior condylar offset after TKR (Pearson correlation coefficient r = -0.06, p = 0.69).

The incidence of fatal pulmonary embolism after primary hip and knee replacement in a consecutive series of 4253 patients

We studied 4253 patients undergoing primary joint replacement between November 2002 and November 2007, of whom 4060 received aspirin only as chemical prophylaxis; 46 were mistakenly given low molecular weight heparin initially, which was stopped and changed to aspirin; 136 received no chemoprophylaxis and 11 patients received warfarin because of a previous history of pulmonary embolism. We identified the rate of clinical thromboembolism before and after discharge, and the mortality from pulmonary embolism at 90 days. The overall death rate was 0.31% (13 of 4253) and the rate of fatal pulmonary embolism was 0.07% (3 of 4253). Our data suggest that fatal pulmonary embolism is not common following elective primary joint replacement, and with modern surgical practice elective hip and knee replacement should no longer be considered high-risk procedures.

Comparison of early postoperative functional levels following total hip replacement using minimally invasive versus standard incisions. A prospective randomized blinded trial

Objective: To compare the results of single-incision minimally invasive total hip replacement (≤ 10 cm) to standard-incision (16 cm) total hip replacement in the early postoperative period with respect to functional and mobilizing ability (transfers, mobilizing, walking and stair assessment). Setting: Orthopaedic wards of a regional orthopaedic centre. Subjects: Two hundred and nineteen total hip replacement patients were tested between December 2003 and June 2004. Interventions: Patients were randomized to either total hip replacement through a minimally invasive (≤ 10 cm) or standard incision (16 cm). A single surgeon performed all procedures using the same type of component fixation. Postoperative physiotherapy assessment and treatment was standardized. Analgesia was also standardized. All patients, physiotherapy staff and assessors were blinded to the incision used. Main outcome measures: Patients were tested two days post operatively and were assessed for the following activities: transfer from supine to sit, transfer from sitting to standing, mobilizing, ascending and descending stairs and weight-bearing. Results: The shorter incision offered no significant improvement in patient ability in relation to transfer from lying to sitting, transfer from sitting to standing, mobilizing or weight-bearing. Ascending/descending stairs gave a total time for the minimal incision of 38.7 s against 40.8 s for a standard incision. There was no difference in walking velocity between the standard incision and minimal incision groups two days post operatively (minimal incision = 0.26 m/s versus standard incision = 0.26 m/s) or six weeks post operatively (minimal incision = 0.90 m/s versus standard incision = 0.93 m/s). There was no difference between groups with respect to walking aids at six-week review. The mean length of stay for the minimally invasive approach was 3.65 days (SD 2.04) against 3.68 days (SD 2.45) for the standard approach. This was not significantly different. Conclusion: Total hip replacement performed through a minimally invasive incision of ≤ 10 cm compared with a standard incision of 16 cm offers no significant benefit in terms of the rate or ability of patients to mobilize and perform functional tasks necessary for safe discharge.

Gait kinematics of age-stratified hip replacement patients—A large scale, long-term follow-up study

Three-dimensional gait analysis data from 134 patients attending routine 10-year post-operative review clinics is presented. Patients were divided into five age groups-54-64 years, 65-69 years, 70-74 years, 75-79 years and over 80 years. A group of 10 normal elderly subjects was also tested. All age groups displayed reduced range of hip flexion/extension, range of knee flexion extension, maximum hip extension and range of hip abduction/adduction and reduced velocity and step length compared to the normal elderly group. However, there was no difference in gait kinematics between the age groups. Patients over 80 years of age displayed significantly reduced range of sagittal plane ankle motion, but this is unlikely to be secondary to hip joint restriction and more likely due to reduced walking speed associated with very elderly subjects. This study reveals that even the youngest hip replacement patients do not attain normal gait kinematics 10-year post-operatively and that muscle atrophy and residual stiffness may influence patient kinematics many years post-operation.

Dislocation of the rotating platform after low contact stress total knee arthroplasty.

From a one-surgeon series of 2485 patients, we report on 10 patients with rotating platform dislocation after primary Low Contact Stress total knee arthroplasty. All dislocations occurred within 2 years of the index procedure. Of the 10 patients, nine required open reduction. Five of these patients also had exchange of the original insert. One patient was treated by closed reduction. All knees were immobilized in a cast for 8 weeks. Eight of the 10 patients had no additional dislocation and at followup (average, 35 months; range, 12 months - 5 years), had a stable functional joint. Two patients had recurrent spinout of the rotating platform develop. One patient had arthrodesis whereas the other patient had the insert cemented to the tibial tray as a salvage procedure. Increasing age, a preoperative valgus deformity, and prior patellectomy were significantly associated with rotating platform spinout. Surgical experience and an improved understanding of the soft tissue constraints, particularly in the valgus knee, are important in minimizing this complication.

Cementless fixation in Oxford unicompartmental knee replacement: A multicentre study of 1000 knees

The Cementless Oxford Unicompartmental Knee Replacement (OUKR) was developed to address problems related to cementation, and has been demonstrated in a randomised study to have similar clinical outcomes with fewer radiolucencies than observed with the cemented device. However, before its widespread use it is necessary to clarify contraindications and assess the complications. This requires a larger study than any previously published. We present a prospective multicentre series of 1000 cementless OUKRs in 881 patients at a minimum follow-up of one year. All patients had radiological assessment aligned to the bone-implant interfaces and clinical scores. Analysis was performed at a mean of 38.2 months (19 to 88) following surgery. A total of 17 patients died (comprising 19 knees (1.9%)), none as a result of surgery; there were no tibial or femoral loosenings. A total of 19 knees (1.9%) had significant implant-related complications or required revision. Implant survival at six years was 97.2%, and there was a partial radiolucency at the bone-implant interface in 72 knees (8.9%), with no complete radiolucencies. There was no significant increase in complication rate compared with cemented fixation (p = 0.87), and no specific contraindications to cementless fixation were identified. Cementless OUKR appears to be safe and reproducible in patients with end-stage anteromedial osteoarthritis of the knee, with radiological evidence of improved fixation compared with previous reports using cemented fixation.

Comparison of hip and knee arthroplasty outcomes at early and intermediate follow-up.

A common perception among clinicians and patients is that recovery is similar following total hip arthroplasty (THA) and total knee arthroplasty (TKA). Improvement in the outcomes of 337 THAs and 256 TKAs implanted by the same surgeon between April 2003 and November 2005 were compared. Improvement was measured using changes in Oxford hip and knee scores measured preoperatively, at first follow-up, and 1 year postoperatively for each patient. Improvements between preoperative review and first follow-up and between preoperative review and 1-year postoperative follow-up were significantly greater for THA compared to TKA patients. Improvements between first postoperative follow-up and 1-year postoperative follow-up were not significantly different between THA and TKA patients. Although THA patients displayed a significantly worse score preoperatively, they displayed a significantly better score at both first follow-up and 1-year postoperative follow-up. While both procedures improve postoperative pain and physical function, as measured by the Oxford score, improvements measured relative to preoperative levels were significantly smaller for TKA compared to THA patients. Despite recent advances in knee arthroplasty surgery, a significant proportion of TKA patients achieve relatively poor outcome scores postoperatively. This study shows that pain and function improve less and more slowly in the early and intermediate postoperative periods for knee compared to hip arthroplasty patients.