Excellent results with femoral revision surgery using an extensively hydroxyapatite-coated stem: 59 patients followed for 10-16 years

Background The outcome of femoral component revision with either cemented or proximally coated stems has been disappointing, but revision with extensively coated stems has been promising. We report long-term outcome of a grit-blasted titanium stem entirely plasma sprayed with hydroxyapatite (HA), in femoral revision surgery.

Patients and methods During 1988 to 1993, we performed 66 femoral revisions in 65 patients (49 women) aged mean 58 (28-86) years. 3 patients died before the 10-year follow-up and 4 did not come for the follow-up examination because they had no hip problems, as confirmed by telephone and by a written reply. 1 of these, however, was previously controlled at 10 years. Thus, 59 patients (60 hips) were followed by clinical and radiographic analysis for 10-16 years after femoral stem revision.

Results 1 stem was re-revised due to mechanical failure, and none were revised because of infection. We noticed a low degree of proximal bone loss and a low incidence of distal bone hypertrophy. These observations indicate no significant net transfer of stress proximally to distally, and a somewhat physiological weight distribution from the stem to the femoral bone. The bone changes confirmed a well-fixed femoral component in asymptomatic patients.

Interpretation Our findings indicate good long-term results with a fully HA-coated stem in femoral revision surgery. ▪     

Charnley low-frictional torque arthroplasty in young rheumatoid and juvenile rheumatoid arthritis: 292 hips followed for an average of 15 years

Introduction In the early 1960s, Charnley was cautious with his patient selection for total hip replacement. As follow-up increased and confidence in the operation grew, younger patients were selected. We present our results of the Charnley LFA in young patients with rheumatoid and juvenile rheumatoid arthritis with a followup of up to 36 years.

Patients We studied 292 Charnley low-friction arthroplasties in 195 young patients with an established diagnosis of rheumatoid arthritis. Their mean age at operation was 38 (12-50) years; 168 (58%) were receiving steroids and 79 (27%) were on non-steroidal antiinflammatory medication. The mean follow-up for the whole group was 15 (1-36) years. 24 patients could not be traced (33 hips), and 61 patients died (88 hips).

Results 25 patients (41 hips) had had a revision. The main indication for revision was cup loosening. In the 85 patients (130 hips) attending follow-up, their mean age at surgery was 36 (17-50) years and the mean follow-up was 20 (10-36) years. 98% were pain-free or had no more than occasional discomfort, 44% claimed to have normal or near-normal function, while 62% had full or almost full range of movement of the replaced hip. Radiographically, 29 cups (22%) were considered to be loose. 1 stem (1%) was definitely loose and 2 stems (2%) were probably loose. With revision for any indication as the endpoint, the survival was 74% at 25 years follow-up.

Interpretation The Charnley LFA continues to be an excellent hip replacement, even for very young rheumatoid arthritis patients. Wear and aseptic cup loosening are the main long-term problems.     

Structural allografts for bone stock reconstruction in two-stage revision for infected total hip arthroplasty: good outcome in 16 of 18 patients followed for 5-14 years

Background The use of massive bone allografts in cases of revision of failed total hip arthroplasties (THAs) due to infection is controversial.

Patients and methods 18 patients presented with infection at the site of a THA and were treated with a two-stage protocol. In the first stage, the prosthesis was removed together with all necrotic tissues and cement material if present. A custom-made mold of Palacos R cement containing 1 g of gentamicin was then inserted in 17 of the 18 patients. Systemic antibiotics were used during the interval period. In the second stage, the patients had either acetabular or femoral reconstruction using bulk allograft bone.

Results Mean follow-up was 9 (5-14) years. 1 patient presented with recurrent infection and underwent a Girdlestone resection arthroplasty as definitive treatment. Another patient had a mechanical failure of the acetabular component, which was revised 10 years after the second stage of the reconstruction. The mean Harris Hip Score improved from 34 points preoperatively to 71 points at the last review. By our definition, 16/18 of the patients had a successful outcome.

Interpretation Our results support the use of massive allografts in staged reconstructions of infected THAs complicated by considerable bone loss. ▪     

Trochleaplasty for patellar instability due to trochlear dysplasia: A minimum 2-year clinical and radiological follow-up of 19 knees

Background Recurrent patellar dislocation may be associated with trochlear dysplasia. Trochleaplasty is a surgical procedure which strives to deepen the trochlear groove. We evaluated the clinical and radiological effect of trochleaplasty after a minimum follow-up of 2 years.

Patients and methods We examined 19 knees in 16 patients at a mean of 3 years after trochleaplasty. Postoperatively, a subjective questionnaire, a Kujala score, and tests for potential patellar redislocation and apprehension were evaluated. On radiographs we evaluated the preoperative and postoperative crossing sign, trochlear depth, trochlear bump, and patellar height. On CT scans, the pre- and postoperative tibial tuberosity to trochlear groove distance (TTTG) and the patellar inclination angle were measured.

Results 16 of 19 knees improved subjectively. The Kujala score increased from 56 to 80 points at the latest follow-up. None of the patients sustained a redislocation. 5 patients had medial parapatellar tenderness, including 4 with persistent apprehension. Radiological signs of trochlear dysplasia were corrected.

Interpretation Patellofemoral instability with underlying trochlear dysplasia can be treated successfully by trochleaplasty.     

Radiolucent lines and osteolysis along tapered straight cementless titanium hip stems: a comparison of 6-year and 10-year follow-up results in 95 patients

Background The progress of radiolucent lines (RLs) around the stems of cementless hip endoprostheses and their implications for implant survival are unclear.

Patients and methods 150 consecutive total hip replacements (THRs) were performed between January and July 1993. The presence and development of RLs and osteolyses were monitored with a standardized special radiographic technique, and the results were compared at 6 and 10 years of follow-up in 95 patients.

Results At 6 years, RLs were detectable in 43 of 95 patients. RLs with an extension of 50% of the respective zone were present in 35 patients, almost all in Gruen zones 1 and 7. 2 patients presented with osteolysis. At 10 years, the RLs were almost identical—both in number and thickness. Only 1 additional osteolytic lesion had developed; no cup osteolyses were detected, and there was no significant polyethylene wear.

Interpretation The RLs detected at 6 years were virtually unchanged at 10 years. As they did not progress, they would not jeopardize implant stability. However, the osteolyses seen in 3 patients emphasize the importance of follow-up examinations.     

Surgical treatment of posttraumatic stiffness of the elbow: 2-year outcome in 21 patients after a column procedure

Background and purpose Posttraumatic stiffness is a common complication of elbow injury and can result in considerable impairment in daily life. We assessed the outcome in 21 patients treated by a column procedure.

Patients and methods We followed 21 patients (average age 40 (10-76) years, 11 women) for 2 years after surgery for a stiff elbow. Range of motion (ROM) and function (EFA score) were measured preoperatively and at 3,12, and 24 months postoperatively.

Results Before surgery, the mean ROM was 69° (SD 24) and the mean EFA score was 74 (SD 13), which improved significantly to 104° (17) and 91 (6), respectively, after release. There were no significant differences between the postoperative measurements at 3,12, and 24 months. No neurovascular complications were noted; 2 patients developed periarticular ossifications postoperatively.

Interpretation A column procedure results in an increase in motion and functional scores at 2-year follow-up. Outcome at 3 months after treatment is the same as after 2 years.     

Postoperative analgesia in total hip arthroplasty: a randomized double-blinded, placebo-controlled study on peroperative and postoperative ropivacaine, ketorolac, and adrenaline wound infiltration

Background Comfort and lack of pain are important for optimal mobilization after hip replacement. We investigated the efficacy of double wound infiltration.

Patients and methods 40 consecutive patients undergoing total hip replacement were randomized into two groups in this double-blinded study. They received wound infiltration at the end of surgery and through an intraarticular catheter 24 h postoperatively. The catheter was placed at the end of surgery. One group received solutions of ropivacaine, ketorolac, and adrenaline. Patients in the control group were injected with saline instead. The observation period was 6 weeks.

Results The patients who received the analgesic solution had less pain up to 2 weeks postoperatively. They reached an earlier and lower pain minimum during the first days postoperatively, had lower use of analgesia up to day 4 postoperatively, and were more satisfied. Use of analgesic solution resulted in less joint stiffness and better function 1 week postoperatively.

Interpretation Operative and postoperative wound infiltration with multimodal drugs reduces pain and the requirement for analgesics after hip replacement, leading to faster postoperative mobilization.     

Conversion from failed hemiarthroplasty to total hip arthroplasty: a Norwegian Arthroplasty Register analysis of 595 hips with previous femoral neck fractures

Background and purpose Conversion total hip replacement (THR) is a common procedure after failed hemiarthroplasty, but there have been few reports describing the long-term outcome of this procedure.

Patients and methods Between 1987 and 2004, 595 THRs were reported to the Norwegian Arthroplasty Register as conversion THR for failed hemiarthroplasty after a femoral neck fracture in patients aged 60 years and older. 122 operations left the femoral stem intact, whereas 473 were converted with exchange of the femoral stem.

Results We found a lower risk of failure (revision surgery for any reason) for the conversion procedures with stem exchange (RR = 0.4; 95% CI: 0.25-0.81) than for the conversion procedures that retained the femoral stem. For the 473 conversion arthroplasties with exchange of the stem, we found no difference in risk of failure compared to all revision stems in the register, either for the complete prosthesis (RR = 0.8; CI: 0.50- 1.20) or for the stem (RR = 0.9; CI: 0.53-1.59). However, for the 122 conversion procedures in which the femoral stem was retained, we found a significantly increased risk of failure for both the complete prosthesis (RR = 4.6; CI: 2.8-7.6) and for the acetabular cup (RR = 4.8; CI: 2.3-10) compared to primary hip arthroplasties.

Interpretation Our findings indicate that the seemingly easy operation of implanting an acetabular cup to convert a hemiarthroplasty to a total hip arthroplasty is an uncertain procedure and that the threshold for replacing the stem should be low.     

Outcome of undisplaced and moderately displaced femoral neck fractures

Background The optimal treatment for femoral neck fracture is a matter of controversy. We compared the outcome of displaced fractures with good healing potential (moderately displaced fractures) to the outcome of undisplaced fractures treated by internal fixation with 2 parallel screws.

Methods In a consecutive series of hip fracture patients, the rates of reoperation and mortality for 225 undisplaced fractures were compared to those for 241 moderately displaced fractures. The patients were followed for 1-6 years.

Results The total rate of reoperation was 19% (9% because of healing complications) for the undisplaced fractures and 33% (20% because of healing complications) for the moderately displaced fractures. Fracture displacement was the main predictor of reoperation. There was no difference in mortality between the groups, and patient-related background parameters (rather than fracture displacement) were the main predictors of mortality.

Interpretation Undisplaced fractures should be treated by internal fixation. The best treatment for moderately displaced fractures remains to be determined.     

Postoperative clodronate decreases prosthetic migration: 4-year follow-up of a randomized radiostereometric study of 50 total knee patients

Background We have previously reported that 6 months of oral treatment with clodronate reduced the migration of the NexGen total knee prosthesis during the first postoperative year, as measured by radiostereometry (RSA). We now report the 4-year results.

Methods This was a double-blind randomized study, using RSA with maximal total point motion (MTPM).

Results With analysis according to the “intention to treat” principle, the only remaining difference between the groups at 4 years was reduced rotation around the transverse axis (a secondary variable) in the clodronate group. However, 3 patients (all clodronate) did not take any tablet after surgery. If they are excluded, there was an almost statistically significant difference between the groups at 4 years regarding MTPM from baseline, with the clodronate group showing 25% less migration. From 1 to 4 years, there was no difference in migration rate by MTPM, but there was a continuous increase in rotation around the transverse axis in the controls, which differed from the clodronate group. There were no cases of aseptic loosening. 2 patients had migration of more than 1.3 mm from baseline to 4 years; neither of them had taken clodronate. The others had migration of less than 0.9 mm.

Interpretation Because migration was clearly reduced by clodronate during the first postoperative year, and there was still a difference at 4 years when analyzed per protocol, it appears likely that this treatment can diminish the risk of loosening. The difference in the number of outliers also points in this direction, and may be more relevant than mean migration values.     

Risk factors associated with acute hip prosthetic joint infections and outcome of treatment with a rifampinbased regimen

Background and purpose Acute prosthetic infection is a serious problem. We report factors related to the incidence of acute infection and results of combined joint debridement and prolonged rifampicin-based antibiotic therapy.

Patients and methods Between 1998 and 2004, 14 acute infections occurred after 819 primary hip arthroplasties. The association between patient-related and surgical factors and the risk of infection were analyzed. Infections were treated with multiple joint lavage, debridement, 2 weeks of antibiotic therapy, and then oral antibiotics for a minimum of 6 months.

Results There was a correlation between having a body mass index (BMI) of ≥ 30, and also more than 2 co-morbidities, and an increased risk of infection. Diabetes was a potential risk factor. Following our regime of treatment, 11 of 14 patients retained their prosthesis. 2 of 3 who required resection arthroplasty underwent successful staged revision, while the third patient had no further surgery because of being deemed unfit.

Interpretation Primary joint replacement was salvaged in 11 of 14 patients. When successful re-implanta-tion was included, 13 of 14 patients had a mobile prosthetic joint without further infection.     

Low metacarpal index predicts hip fracture: a prospective population study of 3,561 subjects with 15 years of follow-up

Background Metacarpal index (MCI), measured from hand radiographs as the ratio between combined cortical thickness and bone diameter, has been suggested for assessment of bone mass and risk of osteoporotic fracture. We studied MCI for its ability to predict hip fractures.

Methods Hand radiographs were taken and MCI determined in 3,561 subjects from a representative population sample of 8,000 Finns who were 30 years of age or over in 1978-80. Record linkage to the National Hospital Discharge Register identified 117 subjects who had been hospitalized for primary treatment of hip fracture by the end of 1994.

Results High age, low body mass index, tall stature and smoking at baseline showed, independently of each other, significant associations with low MCI. Low MCI was a strong predictor of hip fracture. When adjusted for all potential confounding factors, the relative risk of hip fracture per decrement of MCI by one standard deviation (0.1) was 1.5 (95% CI 1.2-1.8).

Interpretation Low MCI is associated with known risk factors of osteoporosis and predicts hip fracture. Since hand radiographs are easily available at low cost, measurements of MCI can be used as an alternative approach to find osteoporotic individuals with a high risk of hip fracture. ▪     

Comparison of analog and digital preoperative planning in total hip and knee arthroplasties. A prospective study of 173 hips and 65 total knees

Introduction Digital correction of the magnification factor is expected to yield more accurate and reliable preoperative plans. We hypothesized that digital templating would be more accurate than manual templating for total hip and knee arthroplasties.

Patients and methods Firstly, we established the interobserver and intraobserver reliability of the templating procedure. The accuracy and reliability of digital and analog plans were measured in a series of 238 interventions, which were all planned using both techniques.

Results Interobserver reliability was good for the planning of knee arthroplasties (κ-values 0.63-0.75), but not more than moderate for the planning of hip arthroplasties (κ-values 0.22-0.54). Analog plans of knee arthroplasties systematically underestimated the component sizes (1.1 size on average), while the digital procedure proved to be accurate (0.1-0.4 size too small on average). The following figures show percentage of cases receiving a correct implant, allowing an error of one size. Digital templating of the hip arthroplasty was less frequently correct (cemented cup and stem: 72% and 79%; uncemented cup and stem: 52% and 66%) than analog planning (cemented cup and stem: 73% and 89%; uncemented cup and stem: 64% and 52%).

Interpretation Planning of component sizes for total knee arthroplasties is an accurate procedure when performed digitally. Our digital preoperative plans which were performed by someone other than the surgeon were less accurate than the analog plans prepared by the surgeon.     

Are distal radius fractures due to fragility or to falls? A consecutive case-control study of bone mineral density, tendency to fall, risk factors for osteoporosis, and health-related quality of life

Background A fracture of the distal radius is considered to indicate an increased risk of future fractures, especially a hip fracture. The main causes may be osteoporosis or a tendency to fall, separately or in combination.

Methods 93 women and 5 men with a recent radius fracture and the same number of controls were measured with a heel-DXL and asked to complete one questionnaire on their quality of life (SF-36), and one on risk factors.

Results The mean T-score of the patients was -2.1, and for the controls it was -1.9 (p = 0.3). The patients aged over 64 years had a history of falling more often than the corresponding controls (p = 0.01), but there was no difference in T-score. By contrast, patients 45-64 years of age showed a non-significant, lower T-score (p = 0.09), but there was no difference concerning their history of falling. For all other risk factors, no differences were found between the patients and the controls. There were significant differences between the patients and the controls in some of the functions in the SF-36, due to the radius fracture.

Interpretation This study indicates that the underlying cause of a distal radius fracture may be different in patients aged 45-64 years and those who are more than 64 years old.     

Selective COX-2 inhibitor versus indomethacin for the prevention of heterotopic ossification after hip replacement: a double-blind randomized trial of 100 patients with 1-year follow-up

Introduction Recent reports have suggested that selective COX-2 inhibition may be sufficient for the prevention of heterotopic ossification.

Methods We performed a randomized controlled study to evaluate the effect of the selective COX-2 inhibitor rofecoxib compared to that of indomethacin on the incidence and extent of heterotopic ossification in patients who had undergone hip replacement surgery. 50 patients received a daily dose of 25 mg rofecoxib and 50 patients received a daily dose of 100 mg indomethacin (25, 25, and 50 mg).

Results No ossifications were found in 48 patients. Grade-II ossifications were seen in 5/46 patients in the rofecoxib group and in 6/50 patients in the indomethacin group. Grade-III and grade-IV ossifications were seen in 3/46 patients in the rofecoxib group only. The differences were not statistically significant. The study medication had to be discontinued in 2 patients in the indomethacin group, due to dyspepsia.

Interpretation After short-term administration, the selective COX-2 inhibitor rofecoxib was effective in preventing heterotopic ossification after total hip arthroplasty.     

Safe fixation with two acetabular screws after Ganz periacetabular osteotomy

Background and purpose With Ganz periacetabular osteotomy, the osteotomized acetabular fragment is reoriented in an adducted, extended, and rotated position. The acetabular fragment is fixated with 2 screws and the patients are allowed 30 kg of weight bearing immediately after surgery. We were interested in examining the stability of the reoriented acetabulum after Ganz osteotomy; thus, the migration of the acetabular fragment was assessed by radiostereometry.

Patients and methods 32 dysplastic patients (27 females; 32 hips) were included in the study. Median age was 39 (20-57) years. Radiostereometric examinations were done at 1 week, 4 weeks, 8 weeks and 6 months. Data are presented as mean (SD).

Results 6 months postoperatively, the acetabular fragment had migrated 0.7 (0.8) mm medially, and 0.7 (0.5) mm proximally. Mean rotation in adduction was 0.5° (1.3). In other directions, mean migration was below 0.5 mm/°. There were no statistically significant differences in migration at 8 weeks and 24 weeks postoperatively regarding translation and rotation.

Interpretation Due to the limited amount of migration, we find our postoperative partial weight-bearing regime safe.     

Uncemented metal-on-metal acetabular component: follow-up of 112 hips for a minimum of 5 years

Background Aseptic loosening is the major cause of implant failure. In cemented hip arthroplasty, failure of the acetabular side is mainly due to lysis caused by wear particles. By using an implant with low wear characteristics and by enhancing acetabular fixation using an uncemented implant, we aimed to reduce acetabular lysis and thereby loosening.

Patients and methods This was a retrospective cohort study of 119 hips (101 patients) that had the Uncemented Fitmore cup (Sulzer Orthopedics). In 66 patients, the femoral component was CF-30 (Sulzer) used with cement. In the remaining 35 patients, thrust plate prosthesis (TPP) (Sulzer) was used. Of the 101 patients, 94 (112 hips) were available for study. Mean follow-up of the 94 patients was 7 (5-13) years.

Results The mean preoperative Harris hip score was 38 and the mean postoperative Harris hip score was 89 at the last follow-up. Taking aseptic loosening as the endpoint, the survival rate of the Fitmore cup was 100% at 11 years.

Interpretation The uncemented Fitmore acetabular cup with second generation metal-on-metal articulation showed good results with regard to aseptic loosening in the medium term.     

Continuous psoas and sciatic block after knee arthroplasty: good effects compared to epidural analgesia or i.v. opioid analgesia: a prospective study of 63 patients

Introduction For endoprosthetic knee surgery, intensive postoperative pain therapy is necessary. We therefore evaluated whether the combination of continuous psoas compartment and sciatic analgesia (PSC) is as effective as epidural analgesia (EPI) and whether it provides better analgesia than patient-controlled intravenous analgesia with piritramide (PCA).

Methods We studied 63 patients who underwent total knee arthroplasty (TKA). The PSC group received a combination of continuous psoas and sciatic nerve block, the EPI group an epidural analgesia, and the PCA group an intravenous patient-controlled piritramide pump. Pain scores, satisfaction, flexion and side effects were recorded.

Results Pain scores (0-10) were higher in the PCA group (on movement, day 1/day 2: 7.0/6.5) than in the EPI group (5.0/5.0) and the PSC group (4.0/3.5). Postoperative opioid consumption over 48 h was higher in the PCA group (51 mg) than in the EPI group (0 mg) and the PSC group (0 mg). There were no differences in functional recovery. Pruritus occurred more frequently in the PCA and EPI groups than in the PSC group. Patients receiving a PSC and EPI were more satisfied than those treated with PCA.

Interpretation Analgesia with PSC catheters or EPI catheter is superior to PCA regarding pain levels, analgesic requirements, and patient satisfaction. There was no difference in functional outcome between the 3 groups.     

Comparison of cemented and uncemented fixation in total hip replacement: a meta-analysis

Background The choice of optimal implant fixation in total hip replacement (THR)—fixation with or without cement—has been the subject of much debate.

Methods We performed a systematic review and meta-analysis of the published literature comparing cemented and uncemented fixation in THR.

Results No advantage was found for either procedure when failure was defined as either: (A) revision of either or both components, or (B) revision of a specific component. No difference was seen between estimates from registry and single-center studies, or between randomized and non-randomized studies. Subgroup analysis of type A studies showed superior survival with cemented fixation in studies including patients of all ages as compared to those that only studied patients 55 years of age or younger. Among type B studies, cemented titanium stems and threaded cups were associated with poor survival. An association was found between difference in survival and year of publication, with uncemented fixation showing relative superiority over time.

Interpretation While the recent literature suggests that the performance of uncemented implants is improving, cemented fixation continues to outperform uncemented fixation in large subsets of study populations. Our findings summarize the best available evidence qualitatively and quantitatively and provide important information for future research.     

The Swedish Ankle Arthroplasty Register: An analysis of 531 arthroplasties between 1993 and 2005

Background Whether or not ankles can be replaced with reasonable safety has been the subject of debate. We present the results of a nationwide series of total ankle arthroplasties.

Patients and methods All Swedish hospitals that implant or have implanted modern three-component ankle prostheses reported demographic data and date of index and revision surgery to a central register. After the data had been introduced into a database, prosthetic survival rates with exchange or permanent extraction of components as endpoint were calculated.

Results Of the 531 prostheses implanted, 101 had been revised by June 15, 2006. The overall survival rate at 5 years was 0.78 (95%CI: 0.74-0.82). For the three surgeons who had inserted the majority of the STAR ankles, the survival rates became significantly higher after the first 30 cases had been performed and was estimated to be 0.86 (0.80-0.93) at 5 years. Lower age at index surgery implied increased risk of revision whereas diagnosis or gender did not.

Interpretation Ankle replacement is a valuable alternative to arthrodesis. However, replacing an ankle is a demanding procedure and the survival is not comparable to that after hip or knee replacement. It is obvious that with increasing experience, the results—including prosthetic survival—will improve.