Christian Merle

CT-guided radiofrequency ablation of osteoid osteoma and osteoblastoma: Clinical success and long-term follow up in 77 patients

The purpose of this study was to retrospectively evaluate long-term success of CT-guided radiofrequency ablation (RFA) in patients with osteoid osteoma (OO) and osteoblastoma (OB) including tumors in critical locations. Eighty-one CT-guided RFA procedures were performed in 77 patients with OO (65 patients) and OB (12) including 6 spinal and 15 intra/periarticular tumors. Procedural techniques included multiple needle positions, three-dimensional access planning, as well as, thermal protection techniques. Long-term success was assessed using a questionnaire including, among others, several VAS (visual analogue scale) scores. All patients completed 3-6 months follow-up, overall response to the questionnaire was 64/77 (83.1%). Primary success rate was 74/77 (96.1%) of all patients. Retreatment with RFA in 3 patients resulted in a secondary success rate of 77/77 (100%). Long-term follow-up (mean, 38.5 months; range, 3-92) revealed a highly significant (p<0.001) reduction of all assessed limitation scores reaching normal or almost normal values. One major complication, a cannula break leading to a secondary short hospital stay, occurred. In conclusion, RFA is a safe and effective long-lasting treatment of OO and OB. Advanced procedural techniques aid treating tumors in critical locations and in the coverage of larger tumors. Besides night pain, RFA also greatly improves other factors negatively affecting the quality of life.

Long-term (20- to 25-year) Results of an Uncemented Tapered Titanium Femoral Component and Factors Affecting Survivorship

BackgroundUncemented femoral components in primary total hip arthroplasty (THA) are commonly used today, but few studies have evaluated their survival into the third decade.Questions/purposesWe evaluated (1) survivorship using femoral revision for any reason as the end point; (2) survivorship using femoral revision for aseptic loosening as the end point; and (3) patient-related and surgical risk factors for aseptic stem loosening at a minimum 20-year followup with an uncemented tapered titanium stem.MethodsWe reviewed the clinical and radiographic results of 354 THAs in 326 patients performed between January 1985 and December 1989 using an uncemented grit-blasted, tapered titanium femoral stem. Mean age at surgery was 57xa0years (range, 13–81xa0years). Kaplan-Meier survivorship analysis was used to estimate long-term survival. Minimum followup evaluation was 20xa0years (mean, 22xa0years; range, 20–25xa0years); at that time, 120 patients (127 hips) had died, and four patients (five hips) were lost to followup. Multivariate survival analysis using a Cox regression model was performed.ResultsSurvivorship at 22xa0years with revision of the femoral component for any reason as the end point was 86% (95% confidence interval [CI], 81%–90%). Survivorship for femoral revision for aseptic loosening as the end point was 93% at 22xa0years (95% CI, 90%–96%). Undersized stems (canal fill indexxa0≤xa080%) and stems in hips with cup revision were at higher risk for aseptic loosening (hazard ratio, 4.2 and 4.3, respectively). There was a high rate of acetabular revision in this series (38%), mostly related to smooth-threaded, cementless sockets.ConclusionsUncemented femoral fixation was reliable into the third decade. Age, male sex, and diagnosis were not associated with a higher risk of aseptic loosening.Level of EvidenceLevel IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Late peri-prosthetic femoral fracture as a major mode of failure in uncemented primary hip replacement

Peri-prosthetic femoral fracture after total hip replacement (THR) is associated with a poor outcome and high mortality. However, little is known about its long-term incidence after uncemented THR. We retrospectively reviewed a consecutive series of 326 patients (354 hips) who had received a CLS Spotorno replacement with an uncemented, straight, collarless tapered titanium stem between January 1985 and December 1989. The mean follow-up was 17 years (15 to 20). The occurrence of peri-prosthetic femoral fracture during follow-up was noted. Kaplan-Meier survival analysis was used to estimate the cumulative incidence of fracture. At the last follow-up, 86 patients (89 hips) had died and eight patients (eight hips) had been lost to follow-up. A total of 14 fractures in 14 patients had occurred. In ten hips, the femoral component had to be revised and in four the fracture was treated by open reduction and internal fixation. The cumulative incidence of peri-prosthetic femoral fracture was 1.6% (95% confidence interval 0.7 to 3.8) at ten years and 4.5% (95% confidence interval 2.6 to 8.0) at 17 years after the primary THR. There was no association between the occurrence of fracture and gender or age at the time of the primary replacement. Our findings indicate that peri-prosthetic femoral fracture is a significant mode of failure in the long term after the insertion of an uncemented CLS Spotorno stem. Revision rates for this fracture rise in the second decade. Further research is required to investigate the risk factors involved in the occurrence of late peri-prosthetic femoral fracture after the implantation of any uncemented stem, and to assess possible methods of prevention.

High survival in young patients using a second generation uncemented total hip replacement

PurposeWhilst excellent long-term results with contemporary uncemented stems have been reported for total hip arthroplasty in young patients, the survival rates for the whole reconstruction are often compromised by high failure rates on the acetabular site due to peri-acetabular osteolysis and accelerated wear.MethodsIn patients 60xa0years old or younger, we retrospectively reviewed the results at a minimum of ten years of 89 consecutive uncemented total hip replacements in 88 patients using the press-fit Fitmore acetabular component in combination with the CLS Spotorno stem and a 28-mm Metasul metal-on-metal articulation or a 28-mm alumina ceramic on conventional polyethylene bearing. The mean age at the time of surgery was 49xa0years (range, 25–60). The mean clinical and radiological follow-up was 12xa0years (range, 10–15).ResultsSix patients (six hips) died and two patients (two hips) were lost to follow-up. Five hips were revised: one for deep infection, one for peri-prosthetic femoral fracture, and one for aseptic stem loosening. In two hips an isolated revision of the acetabular liner was performed (one for recurrent dislocation and one for unexplained pain). No revision was performed for accelerated wear, osteolysis or aseptic loosening of the acetabular shell. We could not detect peri-acetabular osteolysis visible on plain radiographs in those hips evaluated radiographically. The Kaplan-Meier survival with revision for any reason as the endpoint was 94% (95% confidence interval, 86–97) at 12xa0years.ConclusionsThe survival rates and the radiological outcomes with this implant combination in this young and active patient group are encouraging when compared to the results reported for other uncemented cups in this age group.

Mobile-bearing lateral unicompartmental knee replacement with the Oxford domed tibial component

The Oxford mobile-bearing unicompartmental knee replacement (UKR) is an effective and safe treatment for osteoarthritis of the medial compartment. The results in the lateral compartment have been disappointing due to a high early rate of dislocation of the bearing. A series using a newly designed domed tibial component is reported. The first 50 consecutive domed lateral Oxford UKRs in 50 patients with a mean follow-up of three years (2.0 to 4.3) were included. Clinical scores were obtained prospectively and Kaplan-Meier survival analysis was performed for different endpoints. Radiological variables related to the position and alignment of the components were measured. One patient died and none was lost to follow-up. The cumulative incidence of dislocation was 6.2% (95% confidence interval (CI) 2.0 to 17.9) at three years. Survival using revision for any reason and aseptic revision was 94% (95% CI 82 to 98) and 96% (95% CI 85 to 99) at three years, respectively. Outcome scores, visual analogue scale for pain and maximum knee flexion showed a significant improvement (p < 0.001). The mean Oxford knee score was 43 (SD 5.3), the mean Objective American Knee Society score was 91 (SD 13.9) and the mean Functional American Knee Society score was 90 (SD 17.5). The mean maximum flexion was 127° (90° to 145°). Significant elevation of the lateral joint line as measured by the proximal tibial varus angle (p = 0.04) was evident in the dislocation group when compared with the non-dislocation group. Clinical results are excellent and short-term survival has improved when compared with earlier series. The risk of dislocation remains higher using a mobile-bearing UKR in the lateral compartment when compared with the medial compartment. Patients should be informed about this complication. To avoid dislocations, care must be taken not to elevate the lateral joint line.

Minimum ten-year results of a 28-mm metal-on-metal bearing in cementless total hip arthroplasty in patients fifty years of age and younger

PurposeConcerns have been raised in relation to metal-on-metal (MoM) articulations with catastrophic soft-tissue reactions due to metal debris. We reviewed how small head MoM articulations perform in primary uncemented total hip arthroplasty (THA) in young patients at a minimum of ten years.MethodsWe retrospectively evaluated the clinical and radiographic results of the first 100 consecutive primary cementless THAs using the 28-mm Metasul MoM articulation in 91 patients younger than 50xa0years of age at the time of surgery.ResultsAfter 13 years, survival for the endpoint revision due to any reason was 90.9xa0% and 98.9xa0% for revision due to aseptic implant loosening. The cumulative incidence of MoM related revisions was 1.2xa0%. Small proximal femoral osteolysis was found in 18xa0% of hips. No acetabular osteolysis or loosening was detected. Two hips showed signs of femoral neck impingement with severe damage to the neck.ConclusionsEarly in the second decade, MoM-associated complications were rare using the 28-mm Metasul articulation, and aseptic loosening was not a major mode of failure in this cohort of young patients.Level of evidenceTherapeutic Level IV.

Total versus unicompartmental knee replacement for isolated lateral osteoarthritis: a matched-pairs study

PurposeThe aim of this study was to compare the functional outcome of patients following unicompartmental knee replacement (UKR) using the Oxford domed lateral UKR to patients who underwent cruciate-retaining total knee replacement (TKR) for isolated osteoarthritis in the lateral compartment.MethodsWith the help of our institutional database, we retrospectively identified 22 matched pairs with regards to age, gender and body mass index (BMI). Functional outcome was measured using the Oxford Knee Score (OKS) and range of motion (ROM). Complications and revisions were recorded.ResultsThe mean follow-up was 22xa0(UKR) and 19xa0(TKR) months, respectively. Patients following UKR had a statistically significant higher mean postoperative OKS and ROM: mean OKS was 43 [standard deviation (SD) 4] for UKR and 37 (SD 9) for TKR, respectively (pu2009=u20090.023); ROM was 127° (SD 13) for UKR and 107° (SD 17) for TKR (pu2009<u20090.001). Additionally the change in score was statistically significant higher in patients following UKR in the OKS (14.3 (SD 6) vs. 9.6 (SD 8)) and in the range of motion (+12° (SD 19) vs. −3° (SD 20)), (pu2009=u20090.041 and pu2009=u20090.01 respectively). Survival at two years using revision for any reason as the endpoint was 96xa0% [95xa0% confidence interval (CI) 72–99] for UKR and 100xa0% for TKR (Log-rank test, pu2009=u20090.317).ConclusionThe functional results of mobile-bearing UKR for isolated osteoarthritis in the lateral compartment compare favourably to those after cruciate-retaining TKR in the short term. To compare survival and complications after both procedures, longer-term follow-up is necessary.

Sports and physical activity after cementless total hip arthroplasty with a minimum follow‐up of 10 years

The present retrospective cohort study was conducted to compare sporting activity levels before and a minimum of 10 years after primary cementless total hip arthroplasty (THA). A consecutive series of 86 patients with a mean age at surgery of 52 years (range, 21–60 years) was evaluated 11 years after surgery (range, 10–12 years). Pre‐ and post‐operative sporting activities were assessed at routine follow‐up using the University of California, Los Angeles activity score and the Schulthess Clinic sports and activity questionnaire. Post‐operative health‐related quality of life was measured using the Short‐Form 36 (SF‐36) questionnaire and compared with age‐matched reference populations from the SF‐36 database. Eleven years after THA, 89% of preoperatively active patients had returned to sport. Comparing sports activity preoperatively (before the onset of symptoms) and 11 years after THA, no significant difference was found for the mean number of disciplines or session length. A significant decline in high‐impact activities was observed, while participation in low‐impact activities significantly increased. Health‐related quality of life compared well against a healthy age‐matched reference population and was significantly higher than in a reference group of patients with osteoarthritis. The majority of patients were able to maintain their physical activity level in the long term after primary cementless THA, compared with the activity level before the onset of restricting osteoarthritis symptoms. However, a change in disciplines toward low‐impact activities was observed.

Return to sports, recreational activity and patient-reported outcomes after lateral unicompartmental knee arthroplasty

Purpose As the indication for unicompartmental knee arthroplasty (UKA) in recent years has been extended to young and more active patients, the expectations concerning the postoperative level of activity are high. The aim of the following study was to survey the activity level and the health-related quality of life of patients following lateral UKA.MethodsForty-five patients were surveyed to determine their sporting and recreational activities at a mean follow-up of 3xa0years (range 2.0–4.3xa0years) after lateral UKA. We also assessed health-related quality of life of our patients at the time of the survey by use of the SF-36 Health Survey.ResultsBefore the onset of the first restricting symptoms, 42 of 45 (93xa0%) patients were active in at least one sport compared to 43 of 45 (96xa0%) patients after surgery resulting in a return to activity rate of 98xa0%. Within 3xa0months, 56xa0% returned to their activities after surgery and 78xa0% within 6xa0months. The mean postoperative UCLA score was 6.7 (±1.5). Two-thirds of the patients reached a high activity level (UCLA ≥7).xa0Most common activities after surgery were biking, hiking and long walks. While high-impact activities showed a significant decrease, low-impact activities showed a significant increase. The main reason for a decrease in patients’ level of activity was precaution. There are no statistically significant differences in the postoperative scores of our patients and those of a matched healthy reference population in the SF-36 scores.Conclusion The results of the present study demonstrate that a vast majority (98xa0%) of our patients independent to age or gender returned to sports and recreational activity after lateral UKA. Two-thirds of the patients reached a high activity level. Activities patients were most participating in were low- or mid-impact, whereas high-impact activities were mostly given up. Further follow-up is necessary to assess the effect of activity on implant fixation and wear.Level of evidenceRetrospective case series, Level IV.

Minimally invasive Oxford medial unicompartmental knee arthroplasty in young patients

AbstractPurposenAdvanced knee arthritis in young patients is a challenging problem that may necessitate surgical treatment. There are few published studies of mobile-bearing unicompartmental knee arthroplasty (UKA) in young patients, while indications have expanded to its use in this demanding patient group.MethodsThe clinical and radiographic results of the first 118 consecutive Oxford medial UKAs (OUKA) using a minimally invasive technique (phase 3) in 101 patients 60xa0years of age or younger at the time of surgery were evaluated. Median age at surgery was 57 (25–60) years. Kaplan–Meier survivorship analysis was used to estimate implant survival.ResultsMean time of follow-up evaluation was five (SD 1.6) years. At final follow-up, three patients (three knees) had died, and two patients (three knees) were lost to follow-up. Five knees were revised: three for unexplained pain, one for early infection and one for bearing fracture. There was one impending revision for progression of osteoarthritis in the lateral compartment. The radiographic review demonstrated that 5xa0% of the knees had progressive arthritis in the lateral knee compartment, of those 2xa0% with full joint space loss and pain. The Kaplan–Meier survival analysis, using revision for any reason as the endpoint, estimated the five-year survival rate at 97xa0% (95xa0% CI 91–99). Ninety-six per cent of the non-revised patients were satisfied with the outcome, and 4xa0% were dissatisfied. The mean Oxford knee score was 41 (SD 7), with 6xa0% of the knees having a poor result. The mean AKSS was 89 (SD 14), mean flexion was 129° (SD 13) and the mean UCLA score was 6.8 (SD 1.5).ConclusionMinimally invasive Oxford medial UKA was reliable and effective in this young and active patient cohort providing high patient satisfaction at mid-term follow-up. Progressive arthritis in the lateral knee compartment was a relevant failure mode in this age group. Most revisions were performed for unexplained pain, while we did not find loosening or wear in any patient.Level of evidenceIV.