Surgical approach had minor association with femoral stem migration in total hip arthroplasty: radiostereometric analysis of 61 patients after 5-year follow-up.

BACKGROUND AND PURPOSE: Total hip arthroplasty (THA) is usually performed using 1 of 3 surgical approaches: direct lateral (DLA), posterior (PA), or anterior (AA). AA is different from DLA and PA owing to limited intraoperative visibility of the femoral canal. This could affect stem positioning and therefore migration. We aimed to perform an exploratory radiostereometric analysis (RSA) study with 3 groups for surgical approach assessing stem migration up to 5 years postoperatively. PATIENTS AND METHODS: 61 patients with unilateral osteoarthritis of the hip were included. 21 patients were allocated to the DLA, 20 to the PA, and 20 to the AA group. All patients received an uncemented, collarless, double-tapered, fully hydroxyapatite-coated Profemur Gladiator stem. Migration was measured with model-based RSA. Baseline RSA was on day 1 postoperatively. The follow-ups were at day 8, at 5 weeks, and at 3, 6, 12, 24, and 60 months after surgery. Generalized linear mixed models were used to analyze maximum total point motion (MTPM) migrations. RESULTS: Group mean differences in MTPM were 0.4 mm (95% confidence interval [CI] -1.5 to 2.4) for DLA vs. PA, 1.1 mm (CI -1.0 to 3.3) for AA vs. DLA, and 1.6 mm (CI -0.8 to 3.9) for AA vs. PA, when adjusted for sex and age as covariates. 2 stems in the AA group had excessive early migration. For all stems the migrations occurred mainly within 5-week follow-up and then stabilized. CONCLUSION: At 5-year follow-up, there were no statistically significant differences in stem migration associated with the 3 surgical approaches used in this study.

The modified Stulberg classification is a strong predictor of the radiological outcome 20 years after the diagnosis of Perthes' disease.

AIMS: The aim of this study was to assess the prognostic value of the modified three-group Stulberg classification, which is based on the sphericity of the femoral head, in patients with Perthes' disease. METHODS: A total of 88 patients were followed from the time of diagnosis until a mean follow-up of 21 years. Anteroposterior pelvic and frog-leg lateral radiographs were obtained at diagnosis and at follow-up of one, five, and 21 years. At the five- and 21-year follow-up, the femoral heads were classified using a modified three-group Stulberg classification (round, ovoid, or flat femoral head). Further radiological endpoints at long-term follow-up were osteoarthritis (OA) of the hip and the requirement for total hip arthroplasty (THA). RESULTS: There were 71 males (81%) and 17 females. A total of 13 patients had bilateral Perthes' disease; thus 101 hips were analyzed. At five-year follow-up, 37 hips were round, 38 ovoid, and 26 flat. At that time, 66 hips (65%) were healed and 91 (90%) were skeletally immature. At long-term follow-up, when the mean age of the patients was 28 years (24 to 34), 20 hips had an unsatisfactory outcome (seven had OA and 13 had required THA). There was a strongly significant association between the modified Stulberg classification applied atfive-year follow-up and an unsatisfactory outcome at long-term follow-up (p < 0.001). Between the five- and 21-year follow-up, 67 hips (76%) stayed in their respective modified Stulberg group, indicating a strongly significant association between the Stulberg classifications at these follow-ups (p < 0.001). CONCLUSION: The modified Stulberg classification is a strong predictor of long-term radiological outcome in patients with Perthes' disease. It can be applied at the healing stage, which is usually reached five years after the diagnosis is made and before skeletal maturity. Cite this article: Bone Joint J 2021;103-B(12):1815-1820.

Gluteal atrophy and fatty infiltration in end-stage osteoarthritis of the hip: a case-control study.

AIMS: The gluteus minimus (GMin) and gluteus medius (GMed) have unique structural and functional segments that may be affected to varying degrees, by end-stage osteoarthritis (OA) and normal ageing. We used data from patients with end-stage OA and matched healthy controls to 1) quantify the atrophy of the GMin and GMed in the two groups and 2) describe the distinct patterns of the fatty infiltration in the different segments of the GMin and GMed in the two groups. METHODS: A total of 39 patients with end-stage OA and 12 age- and sex frequency-matched healthy controls were prospectively enrolled in the study. Fatty infiltration within the different segments of the GMin and the GMed was assessed on MRI according to the semiquantitative classification system of Goutallier and normalized cross-sectional areas were measured. RESULTS: The GMin was smaller in the OA-group (p < 0.001) compared to the control group, but there was no group difference in the size of the GMed (p = 0.101). Higher levels of fatty infiltration were identified in the anterior segment of the GMin (p = 0.006) and the anterior (p = 0.006) and middle (p = 0.047) segments of the GMed in the OA group. All subjects in the control group had fatty infiltration of the anterior segment of the GMin, but all except one had no fatty infiltration in the entire GMed. CONCLUSION: End-stage OA was associated with significant atrophy of the GMin and higher levels of fatty infiltration, particularly in the anterior segments of the GMin and GMed. Minor fatty infiltration of the anterior segment of GMin appears to be a normal part of ageing. Our study has demonstrated different patterns of atrophy and fatty infiltration between patients with end-stage OA and healthy matched peers.Cite this article: Bone Jt Open 2021;2(1):40-47.

Do Postoperative Results Differ in a Randomized Trial Between a Direct Anterior and a Direct Lateral Approach in THA?

BACKGROUND: The direct lateral approach to THA provides good exposure and is associated with a low risk of dislocations, but can result in damage to the abductor muscles. The direct anterior approach does not incise muscle, and so recovery after surgery may be faster, but it has been associated with complications (including fractures and nerve injuries), and it involves a learning curve for surgeons who are unfamiliar with it. Few randomized trials have compared these approaches with respect to objective endpoints as well as validated outcome scores. QUESTIONS/PURPOSES: The purpose of this study was to compare the direct anterior approach with the direct lateral approach to THA with respect to (1) patient-reported and validated outcomes scores; (2) frequency and persistence of abductor weakness, as demonstrated by the Trendelenburg test; and (3) major complications such as infection, dislocation, reoperation, or neurovascular injury. METHODS: We performed a randomized controlled trial recruiting patients from January 2012 to June 2013. One hundred sixty-four patients with end-stage osteoarthritis were included and randomized to either the direct anterior or direct lateral approach. Before surgery and at 3, 6, 12, and 24 months, a physiotherapist recorded the Harris hip score (HHS), 6-minute walk distance (6MWD), and performed the Trendelenburg test directly after the 6MWD. The patients completed the Oxford Hip Score (OHS) and the EQ-5D. The groups were not different at baseline with respect to demographic data and preoperative scores. Both groups received the same pre- and postoperative regimes. Assessors were blinded to the approach used. One hundred fifty-four patients (94%) completed the 2-year followup; five patients from each group were lost to followup. RESULTS: There were few statistical differences and no clinically important differences in terms of validated or patient-reported outcomes scores (including the HHS, 6MWD, OHS, or EQ-5D) between the direct anterior and the lateral approach at any time point. A higher proportion of patients had a persistently positive Trendelenburg test 24 months after surgery in the lateral approach than the direct anterior approach (16% [12 of 75] versus 1% [one of 79]; odds ratio, 15; p = 0.001). Irrespective of approach, those with a positive Trendelenburg test had statistically and clinically important worse HHS, OHS, and EQ-5D scores than those with a negative Trendelenburg test. There were four major nerve injuries in the direct anterior group (three transient femoral nerve injuries, resolved by 3 months after surgery, and one tibial nerve injury with symptoms that persist 24 months after surgery) and none in the lateral approach. CONCLUSIONS: Based on our findings, no case for superiority of one approach over the other can be made, except for the reduction in postoperative Trendelenburg test-positive patients using the direct anterior approach compared with when using the direct lateral approach. Irrespective of approach, patients with a positive Trendelenburg test had clinically worse scores than those with a negative test, indicating the importance of ensuring good abductor function when performing THA. The direct anterior approach was associated with nerve injuries that were not seen in the group treated with the lateral approach. LEVEL OF EVIDENCE: Level I, therapeutic study.

Less periprosthetic bone loss following the anterolateral approach to the hip compared with the direct lateral approach.

Background and purpose - The loss of bone mineral in the proximal femur following hip arthroplasty may increase the fracture risk around uncemented stems. We hypothesized that the surgical approach to the hip might influence bone mineral changes around the femoral stem in patients with a femoral neck fracture (FNF). Patients and methods - This was a pre-specified subgroup analysis (n = 51) of an ongoing randomized trial (n = 120) in patients with FNF. Participants were allocated to an uncemented hemiarthroplasty inserted through a direct lateral (Hardinge) approach or an anterolateral (modified Watson-Jones) approach. The 51 patients (mean age 83 (70-90) years, 33 women) were measured by dual-energy X-ray absorptiometry (DXA) to assess changes in periprosthetic bone mineral density (BMD). Results - The mean change in total BMD differed between groups at 12 months in favor of the anterolateral group (4.8%, 95% CI 0.0-9.6; p = 0.05). DXA at 3 months displayed BMD loss in the proximal Gruen zones in the lateral group compared with the anterolateral group. Zone 1 (-5.0% vs. 2.7%), zone 2 (-4.3% vs. 4.1%), zone 6 (-6.5% vs. 0.0%) and zone 7 (-11% vs. -2.4%, all p < 0.05). Interpretation - DXA measurements in this study indicate that surgical approach to the hip influences periprosthetic BMD. Clinical implications remain uncertain. Our conclusions should be interpreted with caution as we did not perform adjustments for multiple tests, possibly leading to inflation of false-positive findings.

Radiographic classifications in Perthes disease.

Background and purpose - Different radiographic classifications have been proposed for prediction of outcome in Perthes disease. We assessed whether the modified lateral pillar classification would provide more reliable interobserver agreement and prognostic value compared with the original lateral pillar classification and the Catterall classification. Patients and methods - 42 patients (38 boys) with Perthes disease were included in the interobserver study. Their mean age at diagnosis was 6.5 (3-11) years. 5 observers classified the radiographs in 2 separate sessions according to the Catterall classification, the original and the modified lateral pillar classifications. Interobserver agreement was analysed using weighted kappa statistics. We assessed the associations between the classifications and femoral head sphericity at 5-year follow-up in 37 non-operatively treated patients in a crosstable analysis (Gamma statistics for ordinal variables, γ). Results - The original lateral pillar and Catterall classifications showed moderate interobserver agreement (kappa 0.49 and 0.43, respectively) while the modified lateral pillar classification had fair agreement (kappa 0.40). The original lateral pillar classification was strongly associated with the 5-year radiographic outcome, with a mean γ correlation coefficient of 0.75 (95% CI: 0.61-0.95) among the 5 observers. The modified lateral pillar and Catterall classifications showed moderate associations (mean γ correlation coefficient 0.55 [95% CI: 0.38-0.66] and 0.64 [95% CI: 0.57-0.72], respectively). Interpretation - The Catterall classification and the original lateral pillar classification had sufficient interobserver agreement and association to late radiographic outcome to be suitable for clinical use. Adding the borderline B/C group did not increase the interobserver agreement or prognostic value of the original lateral pillar classification.

Implant Survival After Minimally Invasive Anterior or Anterolateral Vs. Conventional Posterior or Direct Lateral Approach: An Analysis of 21,860 Total Hip Arthroplasties from the Norwegian Arthroplasty Register (2008 to 2013).

BACKGROUND: Since 2008, there has been an increase in the use of minimally invasive surgery (MIS) through an anterior or anterolateral approach for total hip arthroplasty (THA) in Norway. We compared the MIS approaches with the conventional posterior and direct lateral approaches in terms of revision rates and risk of revision. METHODS: On the basis of data in the Norwegian Arthroplasty Register, 21,860 THAs with an uncemented stem, performed between 2008 and 2013, were identified and included in the cohort. Of these THAs, 2,017 were done through an MIS anterior approach; 2,087, through an MIS anterolateral approach; 5,961, through a posterior approach; and 11,795, through a direct lateral approach. Follow-up ended on December 31, 2015. Two and 5-year survival rates were calculated using Kaplan-Meier survival analysis. Relative risk (RR) was calculated using Cox regression analysis, with adjustment for age, sex, primary diagnosis, American Society of Anesthesiologists (ASA) grade, femoral head size, cup fixation, type of articulation, and duration of surgery and using 6 revision end points based on cause: any cause, infection, dislocation, femoral fracture, aseptic loosening, and other/unknown cause. The median duration of follow-up was 4.3 years. RESULTS: There were no significant differences among the surgical approaches with regard to the 2 and 5-year survival rates or RR of revision due to any cause. The RR of revision due to infection was 0.53 (95% confidence interval [CI] = 0.36 to 0.80, p = 0.002) for the MIS anterior and anterolateral approaches and 0.57 (95% CI = 0.40 to 0.80, p = 0.001) for the posterior approach compared with the direct lateral approach. The RR of revision due to dislocation was 2.1 (95% CI = 1.5 to 3.1, p < 0.001) for the posterior approach compared with the direct lateral approach but no significant difference in risk was found when the MIS anterior and anterolateral approaches were compared with the direct lateral approach (RR = 0.71, 95% CI = 0.40 to 1.3, p = 0.25). CONCLUSIONS: The revision rates and risk of revision associated with the MIS anterior and anterolateral approaches were not increased compared with those of the conventional posterior and direct lateral approaches. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Muscular strength after total hip arthroplasty. A prospective comparison of 3 surgical approaches.

BACKGROUND AND PURPOSE: Minimizing the decrease in muscular strength after total hip arthroplasty (THA) might allow patients to recover faster. We evaluated muscular strength in patients who were operated on using 3 surgical approaches. PATIENTS AND METHODs: In a prospective cohort study, 60 patients scheduled for primary THA were allocated to the direct lateral, posterior, or anterior approach. Leg press and abduction strength were evaluated 2 weeks or less preoperatively, 2 and 8 days postoperatively, and at 6-week and 3-month follow-up. RESULTS: Differences in maximal strength change were greatest after 2 and 8 days. The posterior and anterior approaches produced less decrease in muscular strength than the direct lateral approach. 6 weeks postoperatively, the posterior approach produced greater increase in muscular strength than the direct lateral approach, and resulted in a greater increase in abduction strength than the anterior approach. At 3-month follow-up, no statistically significant differences between the groups were found. The operated legs were 18% weaker in leg press and 15% weaker in abduction than the unoperated legs, and the results were similar between groups. INTERPRETATION: The posterior and anterior approaches appeared to have the least negative effect on abduction and leg press muscular strength in the first postoperative week; the posterior approach had the least negative effect, even up to 6 weeks postoperatively. THA patients have reduced muscle strength in the operated leg (compared to the unoperated leg) 3 months after surgery.

Comparison of markers for muscle damage, inflammation, and pain using minimally invasive direct anterior versus direct lateral approach in total hip arthroplasty: A prospective, randomized, controlled trial.

It is proposed that the use of biochemical markers for muscle damage and inflammation provides an objective measure on invasiveness in total hip arthroplasty. We analyzed levels of creatine kinase and C-reactive protein (CRP) after total hip arthroplasty in patients randomized to minimally invasive direct anterior approach or direct lateral approach, also recording consumption of pain medication and levels of pain postoperatively. Eighty-three patients were operated by the use of anterior approach and eighty using lateral. Creatine kinase and CRP levels were measured preoperatively, creatine kinase directly after surgery, and both creatine kinase and CRP on postoperative day 1 through 4. The use of pain medication and levels of pain were recorded. Creatine kinase were higher in the anterior group compared to the lateral group, reaching statistical significance directly postoperative and on day 4. Levels of CRP did not differ, reaching a maximum of mean 52 mg/L on day 3. The use of pain medication was higher in the lateral group on the day of surgery (p = 0.011), and pain levels were higher on all days in the lateral group (p < 0.007). In conclusion, the use of minimally invasive anterior approach caused less pain, but higher postoperative levels of CK, than the use of direct lateral approach.

Good long-term outcome of the untreated contralateral hip in unilateral slipped capital femoral epiphysis : Forty hips with a mean follow-up of 41 years.

PURPOSE: There is no consensus regarding prophylactic fixation of the contralateral hip in slipped capital femoral epiphysis (SCFE). In order to further study this question, we evaluated the long-term natural history of untreated contralateral hips. METHODS: Forty patients treated for unilateral SCFE without evidence of subsequent contralateral slip during adolescence were reviewed with a mean follow-up of 36 years (range 21-50 years). The deformity after SCFE may demonstrate radiographic signs of cam-type femoroacetabular impingement. We, therefore, measured α-angles in the contralateral hips on anteroposterior (AP) and frog-leg lateral radiographs. The angles were compared with those of a control group of adults without SCFE. Five years after the radiographic examination, with a mean follow-up of 41 years, all patients were evaluated by telephone interview. As range of motion and deformity could not be examined, a modified Harris hip score (HHS) (maximum score of 91 points) was used. A modified HHS <76 points and/or radiographic osteoarthritis (OA) was classified as a poor long-term outcome. RESULTS: The mean value of the AP α-angle was significantly higher in the contralateral hips in SCFE patients than in the control group (55° vs. 46°), while the mean value of the lateral α-angle was not. Abnormally high values for one or both α-angles were found in 16 contralateral hips (40 %), of which five patients had abnormal values for both α-angles and were considered to have had an asymptomatic contralateral slip. Five patients (13 %) had a poor outcome in the contralateral hip, of which three patients (8 %) had OA. There was a significant association between hips with both α-angles that were abnormal and poor outcome. CONCLUSIONS: Since the natural history showed good long-term radiographic and clinical outcome in 35 of 40 patients and only three had OA, we conclude that routine prophylactic fixation of the contralateral hip is not indicated.

The acetabulum in Perthes' disease: inter-observer agreement and reliability of radiographic measurements.

BACKGROUND AND PURPOSE: Perthes' disease leads to radiographic changes in both the femoral head and the acetabulum. We investigated the inter-observer agreement and reliability of 4 radiographic measurements assessing the acetabular changes. PATIENTS AND METHODS: We included 123 children with unilateral involvement, femoral head necrosis of more than 50%, and age at diagnosis of 6 years or older. Radiographs were taken at onset, and 1 year and 5 years after diagnosis. Sharp's angle, acetabular depth-width ratio (ADR), lateral acetabular inclination (LAI), and acetabular retroversion (ischial spine sign, ISS) were measured by 3 observers. Before measuring, 2 of the observers had a consensus meeting. RESULTS: We found good agreement and moderate to excellent reliability for Sharp's angle for all observers (intra-class correlation coefficient (ICC) > 0.80 with consensus, ICC = 0.46-0.57 without consensus). There was good agreement and substantial reliability for ADR between the observers who had had a consensus meeting (ICC = 0.62-0.89). Low levels of agreement and poor reliability were found for observers who had not had a consensus meeting. LAI showed fair agreement throughout the course of the disease (kappa = 0.28-0.52). The agreement between observations for ISS ranged from fair to good (kappa = 0.20-0.76). INTERPRETATION: Sharp's angle showed the highest reliability and agreement throughout the course of the disease. ADR was only reliable and showed good agreement between the observers when landmarks were clarified before measuring the radiographs. Thus, we recommend both parameters in clinical practice, provided a consensus is established for ADR. The observations for LAI had only fair agreement and ISS showed inconclusive agreement in our study. Thus, LAI and ISS can hardly be recommended in clinical practice.

Varus femoral osteotomy improves sphericity of the femoral head in older children with severe form of Legg-Calvé-Perthes disease.

BACKGROUND: In the Norwegian prospective study on Legg-Calvé-Perthes disease (LCPD), we found varus femoral osteotomy gave better femoral head sphericity at a mean of 5 years postoperative than physiotherapy in children older than 6.0 years at diagnosis with femoral head necrosis of more than 50%. That study did not include separate analyses for hips with 100% necrosis and those with a percentage of necrosis between 50% and 100%. QUESTIONS/PURPOSES: We asked whether (1) femoral osteotomy improves femoral head sphericity at followup in all patients with more than 50% femoral head necrosis or in selected groups only and (2) there is a critical age between 6.0 and 10.0 years over which femoral osteotomy does not improve the prognosis. METHODS: We treated 70 patients with unilateral LCPD, age at diagnosis of more than 6.0 years, and femoral head necrosis of more than 50% with varus femoral osteotomy between 1996 and 2000. We classified necrosis using the Catterall classification. We established a control group of 51 similar children who received physiotherapy. At the 5-year followup visit, the hips were graded according to femoral head shape: spherical, ovoid, or flat. RESULTS: At 5-year followup, there was no difference between the treatment groups in radiographic outcome in Catterall Group 3 hips. In Catterall Group 4 hips, femoral head sphericity was better in the osteotomy group, with flat femoral heads in 14% compared to 75% after physiotherapy. The same trend toward better head sphericity occurred when the lateral pillar classification was used. CONCLUSIONS: In children aged 6.0 to 10.0 years, in whom the whole femoral head is affected, femoral head sphericity 5 years after femoral osteotomy was better than that after physiotherapy.

[Legg-Calvé-Perthes disease]. / Calvé-Legg-Perthes' sykdom.

BACKGROUND: Legg-Calvé-Perthes disease is characterized by avascular necrosis of the head of the femur. This article deals with the epidemiology, possible causes, treatment and prognostic factors connected with the disease. MATERIAL AND METHOD: The article is based on a non-systematic literature search and own clinical practice, with special emphasis on a Norwegian countrywide study of children with Legg-Calvé-Perthes disease. RESULTS: The incidence of Legg-Calvé-Perthes disease varies in different countries and regions. Those who are older than six years at the time of diagnosis and have over 50% femoral head necrosis have a worse prognosis than younger children where the necrosis is less extensive. Treatment has been discussed extensively over the past 100 years, and still varies considerably. The Norwegian countrywide investigation showed that the results in children who were over six years at the time of diagnosis and had more than 50% femoral head necrosis were significantly better after varus femoral osteotomy than after physiotherapy or orthosis. This agrees with the only other prospective study that has been published. INTERPRETATION: Operative treatment should be considered in children who are six years old or older and have over 50% femoral head necrosis when the diagnosis Legg-Calvé-Perthes disease is made. Those who are younger than six years at the time of diagnosis or who have less than 50% femoral head necrosis should be treated symptomatically. Abduction orthosis has no place in the treatment of Legg-Calvé-Perthes disease.

Long-term outcome of slipped capital femoral epiphysis: a 38-year follow-up of 66 patients.

PURPOSE: The purpose of this retrospective study was to evaluate the long-term outcome of different methods of treatment in slipped capital femoral epiphysis (SCFE), to find risk factors for poor outcome, and to assess whether prophylactic fixation is indicated. METHODS: Sixty-six patients (76 hips) treated for SCFE with a mean follow-up of 38 years (range 21-57 years) were evaluated. All except seven patients had chronic SCFE. Ten patients (15%) had bilateral affection. Three methods of treatment had been used: screw fixation (35 hips), bone-peg epiphysiodesis (30 hips), and bone-peg epiphysiodesis combined with corrective femoral osteotomy (11 hips). The long-term clinical outcome was classified as good when the patient had not undergone total hip replacement (THR), when the Harris hip score (HHS) was 85 points or above, or the patient had no pain. Good radiographic outcome was defined as no THR or osteoarthritis (OA). RESULTS: In 51 patients with chronic slip (mean slip angle 32°) treated with in situ fixation, the clinical outcome was good in 35 patients (69%) and there was no significant difference between screw fixation and bone-peg epiphysiodesis. Eight patients with large chronic slip (mean slip angle 53°) were treated with bone-peg epiphysiodesis and corrective femoral osteotomy, and the clinical outcome was poor in six patients. Seven patients with acute slip had larger mean slip angle (57°) and more complications than those with chronic slip, and the long-term outcome was poor in all. Two hips out of 42 (5%) had OA in the contralateral hip at follow-up. CONCLUSION: In situ fixation of chronic SCFE gave satisfactory long-term outcome irrespective of the treatment method. Corrective femoral osteotomy did not improve the outcome in hips with large slip angles. Acute SCFE had poor outcome. Prophylactic fixation of the contralateral hip is barely necessary.

Immobilization in external rotation after primary shoulder dislocation did not reduce the risk of recurrence: a randomized controlled trial.

BACKGROUND: The treatment of primary traumatic anterior shoulder dislocation varies widely from no immobilization, to two or three weeks of immobilization in internal rotation with the arm in a sling, to treatment with a brace in external rotation. The aim of the present clinical trial was to compare immobilization in internal and external rotation after anterior shoulder dislocation. METHODS: One hundred and eighty-eight patients with a primary anterior traumatic dislocation of the shoulder were randomly assigned to treatment with immobilization in either internal rotation (ninety-five patients) or external rotation (ninety-three patients) for three weeks. The primary outcome measure was a recurrent dislocation within twenty-four months of follow-up. RESULTS: The follow-up rate after a minimum period of two years was 97.9% (ninety-three of ninety-five) in the internal rotation group and 97.8% (ninety-one of ninety-three) in the external rotation group. The compliance rate with the immobilization was 47.4% (forty-five of ninety-five) in the internal rotation group and 67.7% (sixty-three of ninety-three) in the external rotation group. The intention-to-treat analyses showed that the recurrence rate was 24.7% (twenty-three of ninety-three) in the internal rotation group and 30.8% (twenty-eight of ninety-one) in the external rotation group (p = 0.36). CONCLUSIONS: Immobilization in external rotation does not reduce the rate of recurrence for patients with first-time traumatic anterior shoulder dislocation.

The natural history of Perthes' disease.

BACKGROUND: The prognosis in Perthes' disease varies considerably according to certain risk factors, but there is no concensus regarding the relative importance of these factors. We assessed the natural history of the disease and defined prognostic factors of value in deciding the proper treatment. PATIENTS AND METHODS: During the 5-year period 1996-2000, a nationwide study on Perthes' disease was performed in Norway. 425 patients were registered. The present study involved the 212 children (mean age 5.1 years, 77% boys) who were affected unilaterally and who had been treated with physiotherapy only (which is considered not to change the natural history). They were followed by taking radiographs at the time of diagnosis and after 1, 3, and 5 years. At the 5-year follow-up, the outcome was evaluated according to a modification of the Stulberg classification: good (spherical femoral head), fair (ovoid femoral head), and poor (flat femoral head). RESULTS: The 5-year radiographic results were strongly dependent on 4 risk factors: age 6 years or more at diagnosis, total femoral head necrosis, height of the lateral pillar of the epiphysis less than 50% of normal height, and femoral head cover less than 80%. As the number of risk factors increased from 0 to 4, the proportion of patients with good radiographic 5-year outcome decreased from 79% to 0% and the proportion with poor outcome increased from 3% to 91%. INTERPRETATION: Most children under 6 years of age do not need any special treatment. In older children, no special treatment is indicated if the whole femoral head is not necrotic and the femoral head cover is > 80%. In the most severe forms of the disease (i.e. more than 2 risk factors), surgical containment treatment seems advisable.

[Use of MRI for diagnosing scaphoid fracture]. / Bruk av MR ved skafoidfraktur.

BACKGROUND: Oslo accident and emergency clinic (Oslo skadelegevakt) treats most scaphoid fractures in Oslo. The objectives of this study were to assess the usefulness of MRI in diagnosing such fractures and to determine the number of scaphoid fractures treated at our clinic, the number of patients treated with a scaphoid cast without having a fracture, the proportion of these fractures diagnosed with conventional radiographs and that diagnosed with MRI in a given period. MATERIAL AND METHODS: The article is based on a review of medical records from all patients who had taken scaphoid radiographs at Oslo accident and emergency clinic in the period 1 July 2005 - 30 June 2006. RESULTS: 532 patients had their forearm immobilized in a scaphoid cast because of a clinically suspected scaphoid fracture or a diagnosed fracture. 154 of these (29 %) had a scaphoid fracture; 88 (57 %) of them were diagnosed by using conventional radiographs at the first consultation, 8 (5 %) were diagnosed at a second radiographic examination (after 1 to 2 weeks) and 58 (38 %) by use of MRI at a control visit. At the control visit 228 patients were referred to MRI; 91 (40 %) of them had a fracture (58 [25 %] had a scaphoid fracture and 33 [14 %] had other fractures). In children 10 - 14 years of age MRI was used to diagnose 22 of 26 scaphoid fractures. INTERPRETATION: Three of four patients treated with a scaphoid cast due to a suspected scaphoid fracture had no fracture. Early MRI can reduce the time of immobilization for patients without fracture. Use of MRI to diagnose scaphoid fractures probably leads to treatment of some fractures that would heal without immobilization, especially in children who constituted the group most often diagnosed by MRI.

Do Bankart lesions heal better in shoulders immobilized in external rotation?

BACKGROUND AND PURPOSE: Immobilization in external rotation (ER) for shoulder dislocation has been reported to improve the coaptation of Bankart lesions to the glenoid. We compared the position of the labrum in patients treated with immobilization in ER or internal rotation (IR). A secondary aim was to evaluate the rate of Bankart lesions. PATIENTS AND METHODS: 55 patients with primary anterior shoulder dislocation, aged between 16 and 40 years, were randomized to immobilization in ER or IR. Computer tomography (CT) and magnetic resonance imaging (MRI) were performed shortly after the injury. After the immobilization, MRI arthrography was performed. We evaluated the rate of Bankart lesions and measured the separation and displacement of the labrum as well as the length of the detached part of the capsule on the glenoid neck. RESULTS: Immobilization in ER reduced the number of Bankart lesions (OR = 3.8, 95% CI: 1.1 -13; p = 0.04). Separation decreased to a larger extent in the ER group than in the IR group (mean difference 0.6 mm, 95% CI: 0.1 - 1.1, p = 0.03). Displacement of the labrum and the detached part of the capsule showed no significant differences between the groups. INTERPRETATION: Immobilization in ER results in improved coaptation of the labrum after primary traumatic shoulder dislocation.

[Clinical experience with a custom-made hip prosthesis developed in Norway]. / Kliniske erfaringer med en norskutviklet individtilpasset hofteprotese.

BACKGROUND: A custom-made hip prosthesis is developed at St. Olav s Hospital and the Norwegian University of Science and Technology (NTNU) in Trondheim. The purpose was to design an uncemented stem for optimal fit of the proximal femur to achieve secure fixation and optimal strain distribution to the bone. A customized hip prosthesis permits reconstruction of the normal joint mechanism, including reconstruction of leg length, a physiological hip centre and a normal lever arm for the major hip muscles. 6 years of experience with the device at the orthopaedic department at Sørlandet Hospital, Arendal is presented. MATERIAL AND METHOD: 43 hips in 37 patients were operated. Median time of observation was 3 years (3 months-6 years). The patients' age was on average 49 years. 70% of the hips had hip dysplasia. The patients were followed prospectively, both clinically and radiologically for up to 6 years (median 3 years). RESULTS: The operations were performed as planned in all patients with an average operation time of 96 minutes. We have had no re-operations, no post-operative dislocations of the operated hips and no infections. No components have loosened and no patient has complained of thigh pain. One patient had a per-operative femoral fissure that was treated with cerclage, and one patient had an affection of nervus ischiadicus. The mean Harris hip score was 49 pre- and 97 post-operation . INTERPRETATION: Our experience with the Norwegian custom-made hip prosthesis is promising and confirms the good results from the Trondheim group.