Per Adolphson

Periprosthetic proximal bone loss after uncemented hip arthroplasty is related to stem size: DXA measurements in 138 patients followed for 2-7 years.

Background Periprosthetic bone loss occurs around uncemented femoral stems and may be influenced by the stem size. Patients and methods We studied 138 consecutive patients, 3 (2–7) years on average after a total hip arthroplasty operation (THA) for unilateral osteoarthritis with the Bi-Metric uncemented femoral stem. We analyzed Harris hip score and bone mineral density. Results The mean Harris hip score was 97 at follow-up. Bone mineral density decreased proximally by 19% in both Gruen zones 1 and 7. Bone loss in zones 1, 2, 6, and 7 was significantly associated with stem size. Distally, a small gain in bone mass was found in zones 3 and 5 for medium femoral sizes. Interpretation We found a marked proximal BMD loss, especially for the larger stems, which may be specific for this particular implant. Long-term studies should reveal whether this proximal bone loss will affect the longevity of the THA.

Continuous bone loss around a tapered uncemented femoral stem: A long-term evaluation with DEXA

Background Periprosthetic bone loss is a well-docu-mented phenomenon after uncemented total hip arthroplasty (THA); however, little is known about how bone mineral density (BMD) changes after 2 years. Patients and methods 14 patients with hip arthrosis (group A) were operated with a proximally porous- and hydroxyapatite-coated stem and followed for 10 years with DEXA, radiographs and Harris hip score (HHS). Another group of 14 patients (group B) was evaluated at 6 and 14 years using the same prosthesis and protocol. Results No stem was revised and all stems were well-Fixed. At final follow-up, HHS was 97 points in group A after 10 years and 94 points in group B after 14 years. Bone mineral changes in group A were greatest in Gruen zones 1 and 7, where the losses were 31% and 26%, respectively, after 2 years on the operated side. The decrease in BMD continued after 2 years and in Gruen zone 7 it was faster than the rate of bone loss on the control side. In group B, the annual change in BMD on the operated side was not significantly different from the bone loss in group A. Interpretation Up to 14 years after implantation of a tapered uncemented stem, the BMD in the calcar region continues to decrease faster than would be expected from normal ageing.

Wrist function recovers more rapidly after volar locked plating than after external fixation but the outcomes are similar after 1 year

Background and purpose Promising results have been reported after volar locked plating of unstable dorsally displaced distal radius fractures. We investigated whether volar locked plating results in better patient-perceived, objective functional and radiographic outcomes compared to the less invasive external fixation. Patients and methods 63 patients under 70 years of age, with an unstable extra-articular or non-comminuted intra-articular dorsally displaced distal radius fracture, were randomized to volar locked plating (n = 33) or bridging external fixation. Patient-perceived outcome was assessed with the Disability of the Arm, Shoulder, and Hand (DASH) questionnaire and the Patient-Rated Wrist Evaluation (PRWE) questionnaire. Results At 3 and 6 months, the volar plate group had better DASH and PRWE scores but at 12 months the scores were similar. Objective function, measured as grip strength and range of movement, was superior in the volar plate group but the differences diminished and were small at 12 months. Axial length and volar tilt were retained slightly better in the volar plate group. Interpretation Volar plate fixation is more advantageous than external fixation, in the early rehabilitation period.

Epidemiology and changed surgical treatment methods for fractures of the distal radius: A registry analysis of 42,583 patients in Stockholm County, Sweden, 2004–2010

Background and purpose The incidence of fractures of the distal radius may have changed over the last decade, and operative treatment has been commoner during that time. We investigated the incidence of fractures of the distal radius and changing trends in surgical treatment during the period 2004–2010. Patients and methods Registry data on 42,583 patients with a fracture of the distal radius from 2004 to 2010 were evaluated regarding diagnosis, age, sex, and surgical treatment. Results The crude incidence rate was 31 per 104 person-years with a bimodal distribution. After the age of 45 years, the incidence rate in women increased rapidly and leveled off first at a very high age. The incidence rate in postmenopausal women was lower than previously reported. In men, the incidence was low and it increased slowly until the age of 80 years, when it amounted to 31 per 104 person-years. The number of surgical procedures increased by more than 40% despite the fact that there was reduced incidence during the study period. In patients ≥ 18 years of age, the proportion of fractures treated with plating increased from 16% to 70% while the use of external fixation decreased by about the same amount. Interpretation The incidence rate of distal radius fractures in postmenopausal women appears to have decreased over the last few decades. There has been a shift in surgical treatment from external fixation to open reduction and plating.

No adverse effects of early weight bearing after uncemented total hip arthroplasty: a randomized study of 20 patients.

BACKGROUND Few guidelines are available whether early weight-bearing after an uncemented total hip arthroplasty (THA) can be recommended or not. Stability and ingrowth may be jeopardized by immediate loading of the implant while functional recovery may be promoted and periprosthetic demineralization reduced. PATIENTS AND METHODS We did a prospective study of 20 patients who were operated on with a hydroxyapatite-coated (HA), uncemented total hip arthroplasty with a tapered stem because of unilateral arthrosis, and randomized the patients to the immediate (I) or late (L) weight-bearing (after 3 months) group. The shoe on the operated side was equipped with an auditory device signaling when the patient placed a load on the extremity. The clinical assessment was done with the Harris hip score at the time of the operation and after 12 and 24 months. Radiographs and dual-energy x-ray absorptiometry (DEXA) were evaluated for migration, femoral remodeling and bone mineral density (BMD) after 3, 6, 12 and 24 months. Tc-scintigraphy was done after 6, 12 and 24 months. RESULTS Postoperatively, the Harris hip score showed no group difference. After 3 months, we noted a large reduction in BMD around the stem prosthesis. This was most marked in the proximal regions and the bone loss was significantly larger in zone 1, 4 and 5 in the L group. Distally, the BMD normalized with time, but the loss of bone persisted in the proximal zones after 24 months. An initial increase in the scintigraphic uptake ratio in all zones in both groups declined with time, but it was still increased on the operated side after 24 months. Several radiographic signs of bone remodeling were seen, but the patterns were similar in both groups. INTERPRETATION We found no adverse effect of immediate weight bearing with this prosthesis.

The effect of weekly risedronate on periprosthetic bone resorption following total hip arthroplasty: a randomized, double-blind, placebo-controlled trial.

BACKGROUND Bone loss leading to late-occurring periprosthetic femoral fracture is a mode of failure in cementless total hip arthroplasty. The aim of this trial was to investigate the effect of a bisphosphonate, risedronate, on femoral periprosthetic bone resorption following total hip arthroplasty in patients with osteoarthritis of the hip. METHODS We enrolled seventy-three patients between the ages of forty and seventy years who were scheduled to undergo total hip arthroplasty in a single-center, randomized, double-blind, placebo-controlled trial. Subjects were randomly assigned to receive either 35 mg of risedronate (n = 36) or a placebo (n = 37) orally once weekly for six months. The primary end point was the change in bone mineral density in Gruen femoral zones 1 and 7. Bone mineral density scans were made preoperatively and at two days and three, six, twelve, and twenty-four months postoperatively. Secondary end points included migration of the femoral stem and clinical outcome. RESULTS Seventy of the seventy-three patients (thirty-three in the risedronate group and thirty-seven in the placebo group) were analyzed for the primary end point. The mean bone mineral density in zone 1 was 9.2% higher (95% confidence interval [CI], 4.2% to 14.1%) in the risedronate group than in the placebo group at six months postoperatively and 7.2% higher (95% CI, 1.0% to 13.3%) at one year. The mean bone mineral density in zone 7 was 8.0% higher (95% CI, 2.7% to 13.4%) in the risedronate group than in the placebo group at six months postoperatively and 4.3% higher (95% CI, -1.5% to 10.1%) at one year. Migration of the femoral stem, the clinical outcome, and the frequency of adverse events did not differ between the groups. CONCLUSIONS Risedronate taken once weekly for six months following total hip arthroplasty was effective in reducing periprosthetic bone resorption around an uncemented femoral stem up to one year after surgery but had no discernible effect on implant migration or clinical outcome. Future studies of bisphosphonate treatment following total hip arthroplasty should focus on clinically relevant end points such as the risks of fracture and revision arthroplasty.

Evaluation of a Swedish version of the patient-rated wrist evaluation outcome questionnaire: Good responsiveness, validity, and reliability, in 99 patients recovering from a fracture of the distal radius

The patient-rated wrist evaluation (PRWE) form is an established outcome questionnaire designed to measure wrist pain and disabilities in activities of daily living. We translated and validated this score for use in Sweden. The original PRWE score was translated forwards and backwards, and then the responsiveness, validity, and reliability of the Swedish version were tested in 99 patients who were recovering from a fracture of the distal radius. The patients completed the PRWE questionnaire 7 weeks and 4 to 6 months after the injury. Responsiveness was assessed by Standard Response Mean and Effect Size. Content validity was evaluated by examining the proportion of best and worse possible scores. Construct validity was assessed by comparing scores twice after the injury and by comparing patients with fractures of different severity. Criterion validity was evaluated by correlating the PRWE with another upper extremity score: the disability of the arm, shoulder, and hand (DASH) score. Reliability was evaluated with a test-retest and by internal consistency. Responsiveness was excellent (SRM = 1.4–1.7, ES = 1.3). Five patients reported the best possible result after 4 to 6 months but none at 7 weeks, and no patient reported the worst score at any time. The PRWE score corresponded well with improvement and showed good correlation with severity of fracture. The PRWE showed a strong correlation with DASH score (Spearmans rank coefficient = 0.86). Intraobserver reliability of the test-retest and internal consistency was good (Kendall W coefficient = 0.79, Spearmans rank coefficient = 0.99, Cronbachs α = 0.94–0.97). We found this Swedish version of the PRWE to be responsive, valid, and reliable for evaluating the patient-rated outcome after a fracture of the distal radius.

Bone and muscle mass after hip arthroplasty A quantitative computed tomography study in 20 arthrosis cases

We performed a prospective, quantitative computed tomography (QCT) study of bone mineral density (BMD), cortical bone volume, bone mass and muscle volume in 20 patients who were operated on with cemented total hip arthroplasty because of unilateral arthrosis. Both extremities were measured preoperatively, 3 and 6 months after the operation by a single-energy computer tomograph equipped for bone mineral densitometry. Preoperatively, we found a 25 percent decrease in muscle volume of the thigh on the arthrosis side compared to the contralateral side, but only a 6 percent decrease in bone mass, mainly of the cortical bone volume in the middle femur. In the cancellous bone of distal femur and proximal tibia there was a reduction in BMD of 11 and 14 percent, respectively, compared to the contralateral side. After 6 months, we found no changes in cortical bone mass, either on the operated femur or on the contralateral, control femur. The BMD of cancellous bone in distal femur and proximal tibia had not changed. However, the thigh muscle on the operated side showed a strong recovery; 6 months after the operation there was a 19 percent gain on the operated side.

Bone and muscle mass after femoral neck fracture

The cortical bone mineral density (BMD), bone volume, bone mass and muscle volume of the thigh, and the BMD of the distal femur and proximal tibia were measured quantified by quantitative computed tomography (QCT) after an operation for a displaced femoral neck fracture. Twenty patients were randomized to osteosynthesis or total hip arthroplasty (THA). Both legs were scanned after 18 months, and the operated side was compared with the healthy side. Clinical assessment was performed with a Harris hip score. A reference group of 9 patients, who had undergone THA because of arthrosis, was chosen. In the fracture patients, we found a 9% decrease in bone mass and muscle volume of the middle femur. The BMD of the distal femur and proximal tibia showed a more marked osteopenia. There was no difference in these parameters between the two groups. In the reference group of operated arthrosis patients, we did not find any differences between sides postoperatively. After the operation, the fracture patients had a lower Harris score than the arthrosis patients, and this was most pronounced among those who had undergone osteosynthesis. The finding of a marked osteopenia after a femoral neck fracture, irrespective of treatment, but no bone loss after THA because of arthrosis, implies that patients with a femoral neck fracture are more sensitive to osteopenia, and that the bone loss is not proportional to the operative trauma. caused by the disuse and the posttraumatic effect on the bone caused by the operation. Also, the magnitude of the operative trauma may play a role in the development of the osteopenia. Thus, a displaced femoral neck fracture, treated with osteosynthesis or total hip arthroplasty (THA), offers a possibility to distinguish between the osteopenia caused by the fracture and the role of the operation, since the degree of the operative trauma is different. The aim of this study was to investigate whether or not the bone loss after a displaced femoral neck fracture depends on the mode of treatment.

Decrease in bone mineral density and muscle mass after femoral neck fracture: A quantitative computed tomography study in 25 patients

We performed a prospective, longitudinal, quantitative computed tomography (QCT) study of bone mineral density (BMD), cortical bone volume, bone mass and muscle volume in 25 patients who were operated on with osteosynthesis because of a displaced femoral neck fracture. Both legs were scanned within 3 days after the fracture, and 3 and 6 months after the operation. The measurements were performed by a computer tomograph equipped for bone mineral densitometry. We found some side differences among the patients at the time of fracture, but none of the differences was statistically significant. After 6 months, we found reductions in BMD in the distal femur and proximal tibia on the fractured side of 11% and 19%, respectively, as well as a reduction in BMD of 7% in the proximal tibia on the uninjured side. We found no changes in cortical bone mass, either on the fractured femur or on the uninjured femur. The muscles of the thigh showed a loss of 9% on the fractured side, but a gain of 12% on the uninjured side. The findings of a bone loss in the distal femur and proximal tibia of the fractured leg and in the proximal tibia of the healthy leg, but no cortical bone loss in the middle femur on any side 6 months after the fracture, indicate that the cancellous bone is more sensitive to osteopenia. Moreover, this bone loss is interpreted as mainly a posttraumatic effect, since we also found a decrease in bone mineral on the uninjured side, despite a gain in muscle volume on that side, an overuse which was not sufficient to counteract the posttraumatic effect on the bone of the uninjured side.