Preoperative anterior coverage of the medial acetabulum can predict postoperative anterior coverage and range of motion after periacetabular osteotomy: a cohort study.

BACKGROUND: We hypothesized that preoperative pelvic morphology may affect postoperative anterior coverage and postoperative clinical range of motion (ROM) leading to postoperative pincer type femoroacetabular impingement (FAI). The aim of this study was to evaluate the relationships between preoperative bone morphology and postoperative ROMs to prevent postoperative FAI after periacetabular osteotomy. METHODS: Sixty-eight patients (71 hips) with hip dysplasia participated in this study and underwent curved PAO. The acetabular fragment was usually moved only by lateral rotation of the acetabulum, without intraoperative anterior or posterior rotation. The pre- and postoperative three-dimensional center-edge (CE) angles were measured and compared to the postoperative ROM. RESULTS: Preoperative medial anterior CE angle was significantly associated with postoperative anterior CE angle, and the correlation coefficient of medial anterior CE and postoperative anterior CE was higher than the coefficient of preoperative anterior CE and postoperative anterior CE (preoperative anterior CE, rr = 0.27, p = 0.020; preoperative medial anterior CE, rr = 0.54, p < 0.001). Femoral anteversion correlated with postoperative internal rotation angle at 90° flexion (r = 0.32, p = 0.021). In multiple linear regressions, postoperative internal rotation angle at 90° flexion angle was significantly affected by both medial CE angle through the medial one fourth of femoral head and femoral anteversion. CONCLUSIONS: Preoperative medial anterior acetabular coverage was associated with postoperative anterior acetabular coverage. Further, the combination with preoperative medial anterior acetabular coverage and femoral anteversion can predict postoperative internal rotation at 90° flexion. Therefore, the direction of acetabular reorientation should be carefully considered when the patients have high preoperative medial anterior CE angle and small femoral anteversion.

The optimal combined anteversion pattern to achieve a favorable impingement-free angle in total hip arthroplasty.

BACKGROUND: There have been no studies on the differences in impingement-free angle that result from different combined anteversion (CA) patterns. The aim of this study was to find the optimal CA pattern for achieving a favorable impingement-free angle, including bony and prosthetic impingement, in total hip arthroplasty. METHODS: We evaluated 100 patients with no hip arthritis. We investigated the impingement-free angle (flexion, internal rotation with 90° flexion, extension, and external rotation) after changing the stem and cup anteversions to satisfy several CA patterns [cup anteversion + stem anteversion = 30°, 40°, 50°, and 60°; cup anteversion + 0.7 × stem anteversion = 37.3° (:Widmer's theory); and cup anteversion + 0.77 × stem anteversion = 43.3° (:Yoshimine's theory)] using 3-dimensional templating software. RESULTS: The impingement-free angle changed dramatically among the various CA patterns. The optimal CA was changed by various stem anteversion. Only CA: Widmer with stem anteversion of 20° satisfied daily-life range of motion (ROM) requirements (flexion ≥130°, internal rotation with 90° flexion ≥ 45°, extension ≥ 40°, external rotation ≥ 40°). CONCLUSION: Good impingement-free angle cannot be obtained with single fixed CA. Different CA patterns should be used, depending on the differences in the stem anteversion. A CA of 30° with 0° ≤ stem anteversion ≤10°; a CA:Widmer with 20° of stem anteversion; a CA of 40° or Widmer with 30° of stem anteversion. When stem anteversion is ≥40°, CA should be decided by each patient's state. Among them, a stem anteversion of 20° with cup anteversion of 23.3° was found to be the best CA pattern.

Bernese periacetabular osteotomy through a double approach : Simplification of a surgical technique.

OBJECTIVE: Reorientation of the acetabulum to normalize load transfer or avert femoroacetabular pincer impingement to prevent osteoarthritis of the hip. INDICATIONS: Persisting acetabular dysplasia after closure of growth plates or acetabular malrotation. CONTRAINDICATIONS: High dislocation of hip, secondary acetabulum, increased misalignment on functional X­ray, high-grade mobility restriction. Relative: degenerative changes, advanced age. SURGICAL TECHNIQUE: Bernese periacetabular osteotomy through two incisions; all bone cuts are carried out under direct vision. The osteotomies are equivalent to the classic Ganz method. In a slightly tilted forward lateral decubitus position, a posterior incision is applied for the ischium osteotomy and the caudal portion of the retroacetabular osteotomy. The pubis and ilium osteotomies are performed in a supine position through an anterior approach with subsequent reorientation and screw fixation. The rectus femoris is not dissected unless joint exposure is required. POSTOPERATIVE MANAGEMENT: Partial weight bearing with 20 kg for the first 6 weeks postoperatively, followed by stepwise transition to full loads after radiological control. RESULTS: In total, 34 patients (37 hips) were followed up for 20.4 ± 10.3 months. Tönnis osteoarthritis scale levels remained constant. The center-edge angle of Wiberg increased from 13.2 ± 7.5° to 26.5 ± 6.7°, the Tönnis angle (acetabular index) changed from 13.8 ± 6.5° to 3.4 ± 4.4°. At follow-up, the Merle d'Aubigné and Postel score was 16.5 ± 1.4; the modified Harris hip score 87.6 ± 13.9 and the International hip outcome tool (iHOT)-12 78.2 ± 20.3 points. The mean surgical time was 213 ± 29 min. Severe complications were not observed.

What is the tolerated width of periacetabular osteophytes to avoid impingement in cementless THA?: a three-dimensional simulation study.

BACKGROUNDS: Impingement is a risk factor for instability and prosthetic failure following total hip arthroplasty (THA). If the periacetabular osteophytes are not removed at surgery, impingement could occur between the osteophytes and the femoral stem following THA. However, excessive removal of the osteophytes could lead to bleeding from the bone. The aim of our study, therefore, was to locate the site of the impingement and to determine the width of tolerable osteophytes, which does not induce impingement during activities of daily living (ADL), using a three-dimensional simulation. METHODS: On 35 hip models, virtual THA was performed. The acetabular cups were positioned at 45° abduction and 20° anteversion, and the anteversion of femoral stems was 15°. Circular osteophytes with a 30-mm rim were built around the acetabular cup. Fourteen ADL motions were simulated, and the osteophytes were removed until there was no impingement. A clock face was used to map the location and the width of tolerable osteophytes. RESULTS: The impingement mainly occurred in antero-superior and posterior portions around the acetabular cup. Only 4.2-6.2-mm osteophytes were tolerable at the antero-superior portion (12-3 o'clock) and 6.3-7.2-mm osteophytes at the posterior portion (8-10 o'clock) following a total hip arthroplasty. In antero-inferior and postero-superior portions, over-20-mm osteophytes did not induce any impingement. CONCLUSION: Osteophytes in the antero-superior and posterior portion of the acetabulum should be excised during a THA to avoid impingement of the femur-stem construct on the acetabular osteophytes during ADLs.

Surgical treatment of femoroacetabular impingement after slipped capital femoral epiphysis.

PURPOSE OF REVIEW: Femoroacetabular impingement (FAI) post slipped capital femoral epiphysis (SCFE) may lead to degenerative changes on the hip. We have reviewed the current procedures in the literature, aiming to correct the SCFE to prevent FAI and the ones that treat FAI post SCFE. RECENT FINDINGS: The trends of managing moderated or severe SCFE is to correct the displacement by reduction and fixation with articular hematoma decompression in unstable hips and Dunn modified procedure even for unstable and stable situations. However, after FAI is settled, the options are osteochondroplasty by arthroscopy or surgical hip dislocation, associated or not to subtrocanteric osteotomy. SUMMARY: Femoroacetabular impingement may occur in mild slips and certainly occur in cases of moderate and severe slips. The initial management depends on the severity and the stability of the slip.The modified Dunn procedure is a good option for the treatment of unstable SCFEs. Gentle closed reduction with capsulotomy (Parsch) may be considered whenever the surgeon is not comfortable with the modified Dunn procedure.Hips with open physis and stable moderate or severe SCFE, the modified Dunn procedure can be indicated. Cases with closed physis are managed with intertrochanteric osteotomy combined with osteoplasty.In the presence of symptomatic FAI secondary to SCFE, one should consider arthroscopic osteoplasty or surgical hip dislocation (with or without osteotomies) as treatment options.

Periacetabular quadruple osteotomy of the pelvis in older children: computed tomography scan analysis of acetabular retroversion and anterior overcoverage of the hip, preventing femoral acetabular impingement.

The periacetabular quadruple osteotomy of the pelvis (QOP), with the osteotomy of ischial spine to release the sacrospinal ligament, is reserved for older children with low potential of remodeling. Different parameters were studied with computed tomography (CT) scan before (pre-OH) and after surgery (post-OH) and for nonoperated hip (NOH). The study determined an optimal method to avoid retroversion and excessive anterior coverage. Fifteen QOP were performed in 13 patients, ranging in age from 10 to 15 years. The morphology of pelvis was analyzed with a CT scan before the surgery and 2 years after. Pathologies were Legg-Calve-Perthes (seven hips) and dysplasia (eight hips). The two-dimensional exam measured the acetabular index, the coverage, and the version of the acetabulum. The three-dimensional images measured the frontal lateral inclinations of the lips and the sagittal anterior acetabular inclination. The mean anterior acetabular index was 50.4° (NOH), 56° (pre-OH), and 58.7° (post-OH). The posterior acetabular index was 48.5° (NOH), 52.2° (pre-OH), and 40° (post-OH). The anterior coverage angle was 37.1° in (pre-OH), 27.6° (post-OH), and 30.1° (NOH). The posterior coverage was 20.4° (pre-OH), 17.2° (post-OH), and 12.4° (NOH). The acetabular version was 2.1° (pre-OH), 8.3° (post-OH), and 2.5° (NOH). The anterolateral lip inclination was 50.3° (pre-OH), 35.3° (post-OH), and 43.8° (NOH). The posterolateral lip inclination was 56.7° (pre-OH), 43.7° (post-OH), and 55.8° (NOH). The anterior acetabular inclination was 21.3° (pre-OH), 15.6° (post-OH), and 18° (NOH). The QOP enabled significant range of coverage of the hip in adolescents in whom the potential of remodeling is very low. External rotation related to figure-of-four should be omitted, whereas the maneuver to be applied, preventing the anterior impingement and decrease of the posterior coverage, should be performed by placing the acetabular fragment below the iliac bone, with a lateral inclination in the frontal plane similar to a steering wheel movement. This maneuver preserves comparable morphology of the OH with NOH and avoids retroversion with the excessive anterior coverage responsible for pain and early osteoarthritis.

Subcapital Shortening Osteotomy for Severe Slipped Capital Femoral Epiphysis: Preliminary Results of the French Multicenter Study.

BACKGROUND: There is growing evidence that symptomatic femoroacetabular impingement (FAI) can develop after severe slipped capital femoral epiphysis (SCFE) fixed in situ. Realignment procedures have therefore gained popularity, but complication rates remain controversial. Among them, the subcapital shortening osteotomy without hip dislocation has been progressively adopted in France, but results have never been assessed to date. METHODS: All cases performed in 23 French university hospitals between January 2010 and March 2014 were reviewed to (1) describe the surgical procedure, (2) assess the radiologic and functional outcomes, and (3) report complications and more specifically the avascular necrosis rate (AVN) according to initial stability. Stable and unstable SCFE were distinguished following Loder's definition. Radiologic outcomes were assessed by the 3 authors to determine FAI and osteonecrosis rates. Functional outcomes were evaluated at follow-up and complications were reported. RESULTS: A total of 82 cases (45 unstable and 37 stable), performed in 10 institutions, were included with a mean follow-up of 25 months. No intraoperative complication occurred but 2 patients (2.4%) underwent unplanned early revision. Slip angle was significantly reduced (87%) without loss of correction. Overall AVN rate was 9.7%, reaching 13.3% in unstable slips. However, preoperative magnetic resonance imaging showed that most of the unstable epiphyses (4/6) were already hypoperfused before surgery. CONCLUSIONS: The procedure is a reliable option for the treatment of severe SCFE. AVN rates are lower than previously reported in multicenter series of modified Dunn technique, especially in unstable slips. However, the risk of AVN in severe stable SCFE (5.4%) must still be balanced with the functional outcomes of potential future FAI. LEVEL OF EVIDENCE: Level IV-therapeutic study.

Fixation in slipped capital femoral epiphysis avoiding femoral-acetabular impingement.

BACKGROUND: The appropriate treatment in mild slipped capital femoral epiphysis (SCFE) should not only prevent further slipping of the epiphysis but also address potential femoroacetabular impingement by restoring the anatomy of the proximal femur. The aim of this study was to quantify length of the remodeling phase mediated by growth of the femoral neck, after treatment of SCFE with a screw designed to prevent premature closure of the physis and provide stability. METHODS: Between 2001 and 2011, 38 patients with unilateral mild SCFE were treated by fixation in situ using a modified screw which does not cause premature physeal arrest. Twenty-four patients were investigated for clinical and radiological evidence of femoroacetabular impingement immediately after surgery, at 6- and 12-month follow-ups. Statistical analysis was performed comparing measurements of neck length and the α angle of the affected and contralateral side. RESULTS: Mean α angle immediately after pinning was 56.2 ± 10.6° on the anteroposterior view and 91.4 ± 8.2° on the lateral view. These measurements significantly improved at 6 months post-op to 48.9 ± 5.4° on the anteroposterior view and 51.2 ± 6.5° on the lateral view (p < 0.0001). At 12 months from surgery, AP view α angle was 43.0 ± 2.8° (p < 0.0001) and lateral view was 44.2 ± 4.1° (p < 0.0001). We observed a similar growth rate and speed of the femoral neck of both the affected and unaffected sides during the first year of treatment. The clinical results in all patients were rated as excellent. CONCLUSION: Our data supports the use of a surgical technique that allows residual growth of the femoral neck following mild SCFE and permits restoration of the anatomy of the proximal femur while avoiding development of femoroacetabular impingement following mild SCFE.

Effect of soft-tissue impingement on range of motion during posterior approach Total Hip Arthroplasty: an in vivo measurement study.

PURPOSE: While implant impingement and bony impingement have been recognized as causes of poor outcomes in total hip arthroplasty (THA), reports of soft-tissue impingement are rare. To clarify the issue, the effect of anterior capsule resection on hip range of motion (ROM) was quantitatively measured in vivo during posterior approach THA using a CT-based hip navigation system. MATERIALS AND METHODS: For 47 patients (51 hips), hip ROM was measured intraoperatively before and after resection of the anterior hip capsule, and the difference was compared. RESULTS: Resection of the anterior hip capsule brought about an average 6° increase of ROM in the direction of flexion with internal rotation and did not markedly change ROM in other directions. CONCLUSIONS: During THA through a posterior approach, soft-tissue impingement by the anterior hip capsule can occur. Clinically, we expect that resection of the anterior hip capsule can reduce the risk of posterior instability without increasing the risk of anterior instability.

[Impingement Free Motion in Total Hip Arthroplasty - How Can We Implement It?]. / Impingementfreie Bewegung nach Hüft-TEP - wie realisieren?

INTRODUCTION: Prosthetic impingement and insufficient soft tissue tension are still the most important factors responsible for early dislocation after total hip arthroplasty. Optimal positioning of both prosthetic components, the stem and the socket, optimising their design and restoring individual hip biomechanics, are of the upmost importance in reducing the risk of impingement. This study describes the concept of the combined safe zone (cSafe-Zone) that provides guidelines for the optimal positioning of both components. MATERIAL AND METHODS: A computerised CAD model of a total hip prosthesis was used to systematically investigate the effect of design parameters, such as head-to-neck ratio, CCD shaft angle, as well as positioning parameters, such as cup inclination and cup anteversion and stem antetorsion, on the range of motion. We looked for all positioning combinations that allow the predefined range of movement (= iROM, intended range of movement) and thus define the combined safe zone. The analysis was carried out with straight stems, anatomical and short stems. The size of the cSafe-Zone was chosen as the optimising criterion and the largest cSafe-Zone was considered to define the optimal component positions. These optimal relative orientations of cup and stem were engraved onto the surface of the navigation trial head and used to position the cup during surgery. RESULTS: This new combined safe zone is not static but dynamic; it varies in size and position and is specific for each prosthesis system. High stem antetorsion should be combined with lower cup anteversion and vice versa. Thus, cup anteversion and stem antetorsion are complementary. CCD shaft angles above 135° reduce the size of the cSafe-Zone and are therefore not recommended. Larger head sizes allow lower cup inclinations, i.e. the recommended cup inclination for a 28 mm head is 40 to 45°, for 32 mm 38 to 42° and for 36 mm 35 to 40°. This also increases the so-called jumping distance. Anatomical stems require less cup anteversion than straight stems. CONCLUSION: The concept of combined safe-zone delivers clear guidelines how to position both components of a total hip prosthesis in order to maximise range of movement and to reduce the risk of prosthetic impingement. It is the basis of the stem-first surgical technique. Computer-based navigation or mechanical instruments can be used to implement this new concept in surgical practice.

The Hip in Ice Hockey: A Current Concepts Review.

Ice hockey is a fast, physical sport with unique associated biomechanical demands often placing the hip in forced and repetitive supraphysiological ranges of motion. Ice hockey players commonly endure and are sidelined by nebulous groin injury or hip pain. Underlying causes can be chronic or acute and extra-articular, intra-articular, or "hip-mimicking." This article serves to review common hip-related injuries in ice hockey. For each, we define the particular condition; comment on risk factors and preventive strategies; discuss key historical, physical examination, and imaging findings; and finally, suggest nonoperative and/or operative treatment plans.

Even the Intraoperative Knowledge of Femoral Stem Anteversion Cannot Prevent Impingement in Total Hip Arthroplasty.

BACKGROUND: In this prospective study of 66 patients undergoing cementless total hip arthroplasty through a minimally invasive anterolateral approach, we evaluated the impact of an intraoperative hybrid combined anteversion technique on postoperative range of motion (ROM). METHODS: After navigation of femoral stem anteversion, trial acetabular components were positioned manually, and their position recorded with navigation. Then, final components were implanted with navigation at the goals prescribed by the femur-first impingement detection algorithm. Postoperatively, three-dimensional computed tomographies were performed to determine achieved component position and model impingement-free ROM by virtual hip movement, which was compared with published values necessary for activities of daily living. This model was run a second time with the implants in the position selected by the surgeon rather than the navigation program. In addition, we researched into risk factors for ROM differences between the freehand and navigated cup position. RESULTS: We found a lower flexion of 8.3° (8.8°, P < .001) and lower internal rotation of 9.2° (9.5°, P < .001) for the freehand implanted cups in contrast to a higher extension of 9.8° (11.8°, P < .001) compared with the navigation-guided technique. For activities of daily living, 58.9% (33/56) in the freehand group compared with 85.7% (48/56) in the navigation group showed free flexion (P < .001) and similarly 50.0% (28/56) compared with 76.8% (43/56) free internal rotation (P < .001). Body mass index, incision length, and cup size were identified as independent risk factors for reduced flexion and internal rotation in the freehand group. CONCLUSION: For implementation of a combined anteversion algorithm, intraoperative alignment guides for accurate cup positioning are required using a minimally invasive anterolateral approach. Obese patients are especially at risk of cup malpositioning.

[Hips have a hard time in ice hockey goalkeeper's butterfly technique]. / Lonkat kovilla jääkiekkomaa1ivahdin perhostorjunnassa.

Hip problems have increased especially among young ice hockey goalkeepers and those using the butterfly technique. Femoroacetabular impingement (FAI) is a common cause of the symptoms. Although hip impingement may also be symptomless, it may later predispose to joint damages, especially in case of goalkeepers who are loading their hip. Diagnosis of the impingement is important in order to lessen any harmful effects. Magnetic resonance imaging is the most important investigation in addition to the elucidation of patient history and clinical condition. Conservative treatment includes changing the exercise, and making use of exercises supporting the hip. If secondary joint damages have already developed, surgical treatment is required.

Anterior Longitudinal Osteotomy of the Greater Trochanter in Total Hip Arthroplasty.

The extra-articular impingement of the greater trochanter against the ileum is an underrated cause of early dislocation in total hip arthroplasty. In this preliminary study, the authors assess the effectiveness of an anterior longitudinal osteotomy of the greater trochanter for preventing dislocation. A total of 115 patients underwent a total hip arthroplasty through a posterolateral approach. All patients underwent clinical and radiological follow-up at 1, 3, and 6 months. No dislocation was reported. All patients demonstrated fast recovery of range of motion and walking. No trochanter fractures were observed. The osteotomy of the greater trochanter is an effective surgical technique that decreases anterior impingement and consequently lowers the dislocation rate in primary total hip arthroplasty. [Orthopedics. 2015; 38(8):490-493.].

High-grade SCFE: the role of surgical hip dislocation and reduction.

The patient with an unstable slipped capital femoral epiphysis poses a challenging problem to the treating physician to improve the position of the displaced epiphysis to avoid femoroacetabular impingement without developing avascular necrosis (AVN)-a potentially devastating complication. Although the standard operative procedure of in situ pinning following an incidental reduction while positioning the patient on the table, has been the mainstay of treatment in North America, other viable options are available including a surgical dislocation approach to the hip followed by a modified Dunn osteotomy with control of the retinacular vessels, reduction of the epiphysis, and internal fixation with pins or screws. Although technically demanding, this approach offers an opportunity to reduce the epiphysis to avoid femoroacetabular impingement, and limit the possibility for the development of AVN. The early results for this procedure are promising with all studies demonstrating excellent reduction of the epiphysis and an overall lower incidence of AVN when compared with in situ pinning.

Cam deformity and hip degeneration are common after fixation of a slipped capital femoral epiphysis.

BACKGROUND AND PURPOSE: Slipped capital femoral epiphysis is thought to result in cam deformity and femoroacetabular impingement. We examined: (1) cam-type deformity, (2) labral degeneration, chondrolabral damage, and osteoarthritic development, and (3) the clinical and patient-reported outcome after fixation of slipped capital femoral epiphysis (SCFE). METHODS: We identified 28 patients who were treated with fixation of SCFE from 1991 to 1998. 17 patients with 24 affected hips were willing to participate and were evaluated 10-17 years postoperatively. Median age at surgery was 12 (10-14) years. Clinical examination, WOMAC, SF-36 measuring physical and mental function, a structured interview, radiography, and MRI examination were conducted at follow-up. RESULTS: Median preoperative Southwick angle was 22o (IQR: 12-27). Follow-up radiographs showed cam deformity in 14 of the 24 affected hips and a Tönnis grade>1 in 1 affected hip. MRI showed pathological alpha angles in 15 affected hips, labral degeneration in 13, and chondrolabral damage in 4. Median SF-36 physical score was 54 (IQR: 49-56) and median mental score was 56 (IQR: 54-58). These scores were comparable to those of a Danish population-based cohort of similar age and sex distribution. Median WOMAC score was 100 (IQR: 84-100). INTERPRETATION: In 17 patients (24 affected hips), we found signs of cam deformity in 18 hips and early stages of joint degeneration in 10 hips. Our observations support the emerging consensus that SCFE is a precursor of cam deformity, FAI, and joint degeneration. Neither clinical examination nor SF-36 or WOMAC scores indicated physical compromise.

Diagnosis and management of developmental dysplasia of the hip from triradiate closure through young adulthood.

The current treatment of painful hip dysplasia in the mature skeleton is based on acetabular reorientation. Reorientation procedures attempt to optimize the anatomic position of the hyaline cartilage of the femoral head and acetabulum in regard to mechanical loading. Because the Bernese periacetabular osteotomy is a versatile technique for acetabular reorientation, it is helpful to understand the approach and be familiar with the criteria for an optimal surgical correction. The femoral side bears stigmata of hip dysplasia that may require surgical correction. Improvement of the head-neck offset to avoid femoroacetabular impingement has become routine in many hips treated with periacetabular osteotomy. In addition, intertrochanteric osteotomies can help improve joint congruency and normalize the femoral neck orientation. Other new surgical techniques allow trimming or reducing a severely deformed head, performing a relative neck lengthening, and trimming or distalizing the greater trochanter. An increasing number of studies have reported good long-term results after acetabular reorientation procedures, with expected joint preservation rates ranging from 80% to 90% at the 10-year follow-up and 60% to 70% at the 20-year follow-up. An ideal candidate is younger than 30 years, with no preoperative signs of osteoarthritis. Predicted joint preservation in these patients is approximately 90% at the 20-year follow-up. Recent evidence indicates that additional correction of an aspheric head may further improve results.

[Complications after minimally invasive total hip arthroplasty]. / Komplikationen nach minimal-invasiver Hüftendoprothetik.

BACKGROUND: The goal of minimally invasive surgery in total hip arthroplasty (MIS-THA) is reduction of surgical trauma without any limitations regarding exposure of the femur and acetabulum to achieve reproducible results. Despite improved instrumentation the implementation of these techniques is associated with a risk of higher complication rates. AIM: The article describes specific and unspecific complications of MIS-THA and gives hints and tips on how to avoid them. MATERIAL AND METHODS: In a retrospective study 152 THA revisions following MIS-THA were examined and an error analysis was performed. RESULTS: The study of 152 MIS-THA revisions included 87 female and 65 male patients. A gender-specific incidence of complications could not be found. The most common indication for revision surgery was due to recurrent dislocation. An increased incidence of fractures of the greater trochanter was observed using the anterolateral approach with the patient in a supine position. DISCUSSION: The MIS-THA procedure contributes to excellent early rehabilitation when performed correctly. The muscle preserving aspect can be counted as an advantage particularly for young patients. This patient collective has a high risk to undergo revision surgery.

Should all unstable slipped capital femoral epiphysis be treated open?

Historically, in situ fixation has been considered the gold standard for the treatment of unstable slipped capital femoral epiphysis (SCFE). Open treatments can be considered in an attempt to improve outcome, primarily in an effort to decompress the hip or decrease residual deformity. For moderate and severe unstable slips, surgical hip dislocation followed by subcapital realignment has been proposed to address the metaphyseal prominence and prevent impingement. More recently, the natural history of mild slips after in situ pinning has also been questioned and new recommendations involving management with arthroscopic or mini open procedures have been proposed. The purpose of this manuscript is to review the current treatment options and to address the need for open treatments in unstable slipped capital femoral epiphysis.