强直性脊柱炎髋关节强直的中期全髋关节置换术

目的探讨强直性脊柱炎髋关节强直的外科治疗。方法回顾性研究2001年5月—2007年5月24例40髋强直性脊柱炎髋关节强直行关节置换情况,观察术后髋关节功能及并发症。结果随访24～60个月,所有患者髋关节疼痛得到了不同程度的缓解,术后Harris评分提高到60～92分,平均82分。术后6个月所有患者血沉均在30 mm/h以下。结论强直性脊柱炎髋关节强直中期关节置换可改善功能、提高患者生活质量。     

成人强直性髋关节炎分期

目的：探讨强直性髋关节炎如何从平片上判断预后功能分期。方法：100例成人AS髋关节炎，男91例．女9例；根据法定成人年龄．本组最小19岁．只有1例71岁．平均29．9岁。临床主要表现为全身乏力，腰背和髋部疼痛．功能障碍。结果：100例成人强直性脊柱炎．其中7例行MR成像检查。均有骶髂关节和髋火节病理性征象和股骨头灶性坏死。关节间隙不同程度狭窄达95％、股骨头关节边缘滑膜骨化发生率达84％。垂线征是一种骨化线，它从股骨头内下缘向外下至股骨颔，发生牢为69％。100例成人强直性脊柱炎髋臼窝狭窄的发生率高达75％。耻骨联合边缘硬化或吸收和坐骨结节大收肌腱附着点骨化发生率为53％。根据上述综合征象．提出髋关节炎分为4期。Ⅰ期：两侧髋关节变化轻微；Ⅱ期：髋关节狭窄伴随关节周围有明确异常征象；Ⅲ期：髋荚节严蕈狭窄伴随关节周围的严重异常；Ⅳ期：髋关节韧带骨化融合或骨性融合。结论：以髋关节软骨坏死的程度可将强直性髋关节炎分为4期．体现了预后功能的判断。     

Prevention of periarticular ossification following endoprosthetic hip replacement using postoperative irradiation]

The development of heterotopic ossification (HO) after total hip replacement or other surgical hip procedures can considerably impair the functional result and quality of life in up to 73% of all patients. Predisposing high risk factors for heterotopic ossification are severe pre-intra- and/or postoperative hip trauma, previous development of ipsi- and/or contralateral heterotopic ossification, hypertrophic osteoarthritis, active rheumatoid spondylarthritis as well as male sex. Over the past two decades a variety of surgical, pharmaceutical and radiotherapeutic prophylactic measurements have been proposed and tested in clinical trials. Since June 1988, we have treated 77 patients or 80 hips respectively with prophylactic irradiation. Individual risk factors included severe coxarthrosis grade IV, ipsi- or contralateral heterotopic ossification and severe hip trauma. As of July 1991 60 patients with a minimum follow-up of six months could be analyzed using clinical and radiological scoring systems. The patients had been prospectively randomized in two different treatment arms: 32 patients were treated with low dose (LD), five times 2 Gy daily fractions to a total dose of 10 Gy, whereas 28 patients were treated with high dose (HD), ten times 2 Gy (eight patients) or five times 3.5 Gy (20 patients). Operative procedures and individual risk factors were equally distributed in both groups. 23 patients (38% received indometacin three times 25 mg for six weeks, 19 patients (32%) diphosphonate EHDP 20 mg/kg body weight and 18 patients (30%) had no additional medication. 56/60 (93%) patients developed no significant heterotopic ossification and/or remained without impairment of their postoperative radiological and clinical hip status according to the applied Brooker and Harris Scores. Only 4/60 (7%) patients demonstrated treatment failures developing postoperative worsening one grade of Brooker score in two patients and two and three grades of Brooker score in the two others. Only 1/49 patients experienced a treatment failure, when radiotherapy had been initiated before and at postoperative day 4 compared to 3/11 patients initiated after postoperative day 4 (p less than 0.001). 3/32 patients (9.4%) in the LD group and 1/28 (3.6%) in the HD group were scored as treatment failures (nonsignificant). Radiotherapy treatment duration and additional medication had no impact on the outcome. In conclusion postoperative radiotherapy has shown high efficacy in prevention of heterotopic ossification as long as the treatment is initiated within the first four days after surgery. With respect to acute toxicity postoperative radiotherapy seems to be without any competition compared to surgical and pharmaceutical approaches including corticoid, diphosphonate and nonsteroid antiphlogistic drugs.     

强直性脊柱炎严重髋关节病变的相关因素

目的 :了解强直性脊柱炎 (AS)严重髋关节病变的临床特点及相关因素。方法 :对 6 5例严重髋关节病变已行髋关节置换术的AS患者 (A组 )和 130例无髋关节病变的AS患者 (B组 )进行对比分析。结果 :A组发病年龄及病程均短于B组 (P <0 0 5 ) ;以外周关节病起病A组明显高于B组 (P <0 0 1) ;A组全身症状和外周关节炎比B组重 (P <0 0 1) ;ESR ,CRP ,IgG ,IgM及r-球蛋白水平A组均高于B组 (P <0 0 5 ) ;X线检查骶髂关节及脊柱病变两组无明显差异 ;早期用柳氮磺胺吡啶 (SASP)治疗的人数A组少于B组 (P <0 0 5 ) ,早期用激素治疗的人数A组多于B组 (P <0 0 5 )。结论 :发病年龄早、病情进展快 ,以外周关节起病伴全身症状重以及外周关节炎者易发生髋关节严重破坏 ,炎症或免疫反应、早期应用激素可能与髋关节破坏有关。早期用SASP治疗 ,尽量避免用激素 ,可防止或减缓髋关节破坏或其进展     

Seronegative arthritides of the anterior chest wall: a follow-up study

Fourteen patients with arthritis of the anterior chest wall (ACW) as part of ankylosing spondylitis, reactive arthritis, and arthritis associated with psoriasis and/ or pustulosis palmoplantaris (PPP) were re-examined after periods of 5–15 years (mean 9 years) using tomography. The findings were compared with those of 24 similarly examined patients with predominant osseous sclerotic ACW lesions or monarthritis of the manubriosternal joint. Pronounced osseous hyperostosis in the region of the sternoclavicular joint accompanied by ossification of the costoclavicular ligament was found to occur only in patients with PPP lesions. Patients with ankylosing spondylitis and reactive arthritis developed slight or moderate hyperostosis only and no ligament ossification. Predominant osseous sclerotic sternal and clavicular lesions occurred in patients with PPP and in patients without skin disease or traits suggesting well-known arthritides, but not as part of ankylosing spondylitis and reactive arthritis. Arthritis of the manubriosternal joint and upper sternocostal joints developed in all forms of arthritis.     

The fate of the hip in spondylo-epi-metaphyseal dysplasia: clinical and radiological evaluation of adults with SEMD Handigodu type

Purpose

This study was undertaken to document the fate of the hip with reference to its structure and function in patients with spondylo-epi-metaphyseal dysplasia tarda Handigodu type (SEMD_HG).

Material and methods

Radiographs of 271 adult patients with SEMD_HG were studied to identify the pattern of long-term sequelae in the hips. Several measurements of the proximal femur and acetabulum were made to quantify morphological alterations in the hip. Fifty-four adult patients were examined and administered a questionnaire to evaluate the extent of disability attributable to the hips.

Results

Three patterns of changes in the hips were noted: 35% had acetabular protrusio, 33% had subluxation of the hip, and 32% had no protrusio or subluxation. Distinctly different anthropometric measurements and dimensional alterations around the hip were noted in these three patterns. Patients with protrusio were relatively tall while those with subluxation were the shortest. All the patients had developed degenerative arthritis of the hips by the fourth decade of life irrespective of the pattern of hip involvement. The reduction in the range of hip motion and fixed deformities were most severe in patients with protrusio. All the patients had significant disability and very low functional hip scores.

Conclusion

Degenerative arthritis of the hip develops in the majority of patients with SEMD_HG; the symptoms are severe enough to warrant reconstructive surgery by the fourth decade of life. Protrusio or subluxation develops in a third of the patients each; both these complications will influence the surgical approach if total hip arthroplasty is planned.     

"MR corner sign": value for predicting presence of ankylosing spondylitis

OBJECTIVE: The purpose of this study was to evaluate the MRI features of the "MR corner sign" and to determine its diagnostic usefulness in ankylosing spondylitis. We reviewed the spinal MR images of 52 patients with ankylosing spondylitis and compared these images with those of 52 age- and sex-matched control subjects. CONCLUSION: The MR corner sign was defined as a triangular and sharply marginated corner abnormality in a vertebral body unassociated with osteophytes or Schmorl's node. MR corner lesions were significantly more common in the ankylosing spondylitis group than in the control group (Fisher's exact test, p < 0.001). The sensitivity, specificity, and positive and negative predictive values of the MR corner sign were 44%, 96%, 92%, and 63%, respectively. The most frequent feature of signal intensity was a Modic type II change (77%). In patients with ankylosing spondylitis, the MR corner sign was fre quently seen at the thoracolumbar junction, whereas degenerative corner lesions were commonly seen in the lower lumbar spine. When the MR corner sign is detected on spinal MR images in daily practice, it should not be overlooked because it suggests the possibility of ankylosing spondylitis, which should then be further evaluated.     

The application of MR imaging in the detection of hip involvement in patients with ankylosing spondylitis

Objective

To investigate the changes in hip MR imaging, evaluate the frequency of hip involvement and compare the value of clinical symptoms, radiographs, and MR imaging in the detection of hip involvement in patients with ankylosing spondylitis (AS).

Methods

Anteroposterior radiographs of the pelvis, MR imaging of the hip and clinical evaluation were undertaken in 58 patients with definite AS. All patients were followed up 3 years. Annual radiographs and clinical evaluation were carried out. The imaging data were independently assessed by two experienced radiologists who were blinded to patient identity and clinical characteristics. Based on the Bath Ankylosing Spondylitis Radiology Hip Index (BASRI-hip) scoring system, BASRI-hip scores ≥2 were defined as radiological hip involvement. On MR imaging, both acute and chronic inflammatory changes were considered positive signs for hip involvement. Symptomatic hip involvement was defined as current or past pain or limitation of the hip movement. The statistical analysis was performed using the χ² test for comparison of sensitivity among clinical symptoms, radiographs, and MR imaging in the detection of hip involvement and the Student's t-test for comparison of disease duration between with and without hip involvement. A P value <0.05 was considered to be statistically significant. For interpreting MRI and radiographs, the percentage of agreement between the two assessors and the kappa coefficients were calculated.

Results

On MR imaging, positive changes were detected in 86 (74.1%) hips among 116 hips in all 58 patients. Joint effusion was observed in 73 (62.9%) hips; 23 out of 27 patients who underwent fat-saturated contrast-enhanced T₁-weighted sequences had abnormal synovial enhancement in bilateral hips. The other abnormal MR findings included subchondral bone marrow edema in 35 (30.2%) hips, enthesitis in 22 (19.0%) hips, fatty accumulation of the bone marrow in 28 (24.1%) hips, bone erosive destruction in 32 (27.6%) hips, and joint-space narrowing in 4 (3.4%) hips. Based on the BASRI-hip scoring system, 68, 24, 18, 6 and 0 hips had no, suspicious, mild, moderate or severe damage on conventional radiographs of the pelvis, respectively. Thirty-five hips in 20 patients had current or past pain or limitation. The proportion of hip involvement according to MR imaging, radiographs, and clinical symptoms was 74.1% (86/116), 20.7% (24/116), and 30.2% (35/116), respectively. MR imaging yielded higher values than radiographs and clinical symptoms in the detection of hip involvement in patients with AS (χ² = 66.45 and 44.93, P <0.05). Interreader reliability for interpretation of findings was acceptable for both MRI and radiographs. During follow-up, radiological hip involvement were found in 10 hips with BASRI-hip scores ≤1 at baseline and clinical symptoms appeared in 15 sides of the original asymptomatic hip. On baseline MR imaging, inflammatory changes were seen in all hips which appeared symptoms and/or radiological involvement both at baseline and during follow-up.

Conclusion

The proportion of hip involvement is much higher than that suggested by radiographic changes and clinical symptoms. MR imaging is superior to conventional radiographs and clinical symptoms in the detection of hip involvement. Joint effusion and synovial enhancement caused by synovitis are the commonest hip findings on MR imaging in patients with AS.     

强直性髋关节炎平片与MRI分析

目的：分析强直性髋关节炎骨盆骨质疏松的细微结构和骨坏死的病理性征象。方法：收集北亚骨科医院强直性脊柱炎患者100例，其中8例行MR成像检查。分析髋部骨质疏松的特殊性和骨坏死征象以及关节软骨破坏程度。结果：髋部多发区域性骨小梁丢失、减少发生率最高85％，骶髂关节侵蚀破坏或骨性强直为100％，股骨头灶性骨坏死，吸收后表现单囊或多囊状破坏或有小死骨34％，关节破坏狭窄54％，股骨头关节软骨边缘滑膜骨化突出33％，耻骨联合吸收或硬化24％，坐骨结节骨化43％。结论：强直性髋关节炎主要表现为区域性迁移骨疏松和股骨头多发灶性骨坏死。     

Re-irradiation for prophylaxis of heterotopic ossification after hip surgery.

Heterotopic ossification (HO) may occur after total hip arthroplasty, but fortunately most patients are asymptomatic. Rick factors for HO include previous HO, hypertrophic osteoarthritis, diffuse idiopathic skeletal hyperostosis, ankylosing spondylitis, Paget's disease and post-traumatic arthritis. Both pre-operative and post-operative radiotherapy are effective in the prevention of HO in 85-95% of high-risk patients treated. In the few patients who needed re-operation for a variety of reasons, we found that re-irradiation is possible and safe. These case reports present our experience with single dose re-irradiation of the hip in an attempt to prevent post-operative HO.     

强直性脊柱炎髋关节改变的X线、CT和MRI对比研究

目的 探讨强直性脊柱炎(AS)髋关节受累的影像表现,比较X线平片、CT和MRI显示AS髋关节受累的敏感度.方法 对55例AS患者行骨盆X线平片和MR检查,其中29例行髋关节CT检查.MR平扫均包括冠状面T1WI、T2WI、STIR、附加水激励的三维稳态快速梯度回波序列(3D-BTFE-WATS),其中24例同时行脂肪抑制T1WI增强检查.分析患者的影像资料,应用x2检验对X线平片、CT和MRI显示AS髋关节受累改变的敏感度进行分析.结果 55例AS患者110侧髋关节中,X线平片和MRI显示异常分别为13侧和85侧;X线平片改变包括关节面下骨侵蚀破坏13侧、关节间隙变窄4侧、韧带骨赘5侧;MRI显示关节面下骨侵蚀破坏31侧、关节间隙变窄4侧、关节少量积液80侧、骨髓水肿32侧、脂肪沉积28侧、韧带附着点炎21侧,24例行MR增强检查患者中19例见双侧滑膜异常强化.CT检查29例共58侧髋关节,CT在显示X线平片和MRI所显示的骨破坏同时,发现X线平片未能显示的10侧骨破坏和MRI未显示的1侧骨破坏.X线平片、CT、MRI显示异常分别为10.3％ (6/58)、27.6％ (16/58)和77.6％ (45/58),MRI显示髋关节受累的敏感度优于X线平片和CT(x2值分别为53.22和29.08,P值均＜0.05).MRI除显示X线平片和CT所能显示的慢性骨结构改变外,还发现X线平片和CT未能显示的急性炎症改变.结论 MRI能显示X线平片和CT不能显示的AS髋关节受累的急性炎症改变,滑膜炎所致的少量积液和滑膜异常强化是髋关节受累最常见的MRI表现.     

Clinical presentation of femoroacetabular impingement

The purpose of this study was to identify subjective complaints and objective findings in patients treated for femoroacetabular impingement (FAI). Three hundred and one arthroscopic hip surgeries were performed to treat FAI. The most frequent presenting complaint was pain, with 85% of patients reporting moderate or marked pain. The most common location of pain was the groin (81%). The average modified Harris Hip score was 58.5(range 14–100). The average sports hip outcome score was 44.0 (range 0–100). The anterior impingement test was positive in 99% of the patients. Range of motion was reduced in the injured hip. Patients who had degenerative changes in the hip had a greater reduction in range of motion. The most common symptom reported in patients with FAI was groin pain. Patient showed decreased ability to perform activities of daily living and sports. Significant decreases in hip motion were observed in operative hips compared to non-operative hips. Research performed at the Steadman Hawkins Research Foundation, Vail, CO.     

Modest mid-term outcomes after isolated arthroscopic debridement of acetabular labral tears

Purpose

Currently, there is a paucity of literature regarding outcomes after isolated labral debridement. The purpose of this study was to (1) report the reoperation rate following isolated labral debridement, (2) report clinical and functional outcomes after labral debridement with a minimum 2-year follow-up and (3) identify risk factors for worse clinical and functional outcomes. It was hypothesized that inferior outcomes are associated with an increasing Tönnis grade and those with untreated femoral acetabular impingement (FAI).

Methods

The records of patients undergoing hip arthroscopy between 1998 and 2005 were reviewed. Patients with labral tears who underwent isolated arthroscopic labral debridement were identified. Kaplan–Meier estimate of failure (defined as subsequent surgery) was performed for all patients. Patients with minimum 2-year follow-up were assessed with Modified Harris Hip Score (MHHS) and Hip Outcome Score (HOS). Univariate analysis was then performed to assess which factors were associated with worse clinical and functional outcomes.

Results

Fifty-nine hips in 57 patients met our inclusion criteria (39 females, 18 males) with a mean age of 46 ± 14 years and mean follow-up of 5 (range 2–14) years. Overall, 45 % of the hips failed for repeat surgery (20 %) or rating for hip function as abnormal or severely abnormal (25 %). Twelve hips (20 %) required subsequent surgical intervention at a mean 23 (range 6–60) months (7 total hip arthroplasties, 2 open revisions, 3 arthroscopic revisions). Of the remaining hips, mean MHHS was 83.4 ± 19.7, mean HOS ADL score was 83.8 ± 21.3 and mean HOS sport score was 70.6 ± 32.9, with 33 of 41 (75 %) reporting normal or nearly normal current level of function. Univariate analysis revealed that hips with untreated bony impingement (p = 0.01) or requiring concomitant chondroplasty (p = 0.03) had inferior clinical outcome scores.

Conclusions

Isolated arthroscopic labral debridement for hip labral tears had 45 % combined poor results when strictly defining failure as repeat surgery or abnormal hip rating. Untreated FAI and concomitant chondroplasty were risk factors for inferior outcome. We recommend concomitant treatment for bony impingement lesions and preservation of the labrum whenever possible.

Level of evidence

Retrospective case series, Level IV.     

强直性脊柱炎致骶髂关节炎的X线与CT诊断

目的 评估X线对强直性脊柱炎患者骶髂关节炎的诊断价值。方法 对临床表现为缓慢加重的腰骶部及双髋部疼痛、压痛及活动受限者68例，进行脊柱正侧位或加摄斜位X线片。其中，6例临床怀疑骶髂并节病变者又经CT检查。结果 单侧骶髂关节改变为28例，双侧骶髂关节改变40例。怀疑骶髂关节病变6例，轻度骶髂关节炎34例，中度骶髂关节炎20例，重度骶髂关节炎8例。68例中59例HLA—B27抗原阳性。结论 X线正位加左、右斜位平片能对大部分骶髂关节炎作出诊断，尤其是左、右斜位更有利于观察骶髂关节病变。对于骶髂关节炎的早期诊断，CT优于X线平片。     

Methods of the physical medicine therapy in prevention of heterotopic ossification after total hip arthroplasty

BACKGROUND/AIM: In the prevention of periarticular heterotopic ossification (HO), a common complication after total hip arthroplasty (THA), nonsteroidal antiinflammatory drugs (NSAID) and irradiation are used. Some theories presume that local hypoxia of the soft tissue causes HO. The aim of this study was to investigate if the early use of pulsed electromagnetic fields (PEMF) could prevent this ossification since it accelerates the circulation and oxigenation of soft tissue. METHODS: The study included three groups of the patients with primary THA. The group C consisted of 66 patients/79 hips who had only kinesitherapy in postoperative rehabilitation. The group B consisted of 117 patients/131 hips who had PEMF and interferential current (IC) which, on average, started on the 14th day after the surgery combined with the standard kinesitherapy. The group A consisted of 117 patients/131 hips who had PEMF from the third postoperative day and IC from, on average, the 14th postoperative day with the standard kinesitherapy. The classification of HO was done on a standard AP roentgenograms of the hips, taken at least one year after the surgery. RESULTS: The overall HO was seen in 50.63% of the group C patients, in 43.51% of the B group and in 16.67% of the group A. Severe HO (III and IV class according to Brooker) was seen in 26.58% of the group C patients and in 6.10% of the group B, but none in the group A. CONCLUSION: According to the obtained results an early treatment with PEMF could prevent severe HO and reduce the overall HO.     

A new operative approach in the correction of external coxa saltans: the snapping hip

BACKGROUND: External snapping hip is an entity that describes a snap that is felt on the lateral aspect of the hip. Several surgical interventions are described. HYPOTHESIS: The external snapping hip can be corrected with a simple procedure that is minimally invasive and less demanding than other techniques. STUDY DESIGN: This is a retrospective review from June 1994 until January 2002 looking at released external snapping hips. METHODS: There were 16 patients with 17 hips; follow-up was in 15 patients with 16 snapping hips. Twelve patients with 13 hips were contacted by telephone interview, and 3 were followed up by their most recent chart note. All underwent the same procedure performed by the senior author. The questionnaire was conducted at an average of 32.5 months after surgery (range, 9-74 months). For 3 patients, chart-only follow-up was at 6 weeks, 3 months, and 6 months, respectively. RESULTS: Fourteen of 16 hips remained asymptomatic after final surgical release (2 hips needed a second release). All patients contacted by telephone would undergo the same procedure again if faced with the same symptoms. CONCLUSIONS: This technique is simpler than most of those previously described with the benefit of no formal postoperative regimen and comparable results.     

Morphological analysis of the knee joint in patients with hip dysplasia

Purpose

The purpose of this study was to investigate the morphological changes of the knee in patients with untreated developmental dysplasia of the hip.

Methods

Morphological analysis of 150 knee joints in 75 patients with developmental dysplasia of the hip was performed by examining computed tomographic (CT) images. Of these patients, 36 had unilateral developmental dysplasia of the hip and 39 had bilateral developmental dysplasia of the hip. Therefore, 36 hips were normal, and 114 hips were dislocated. CT images ranged from the iliac crest to 2 cm inferior to the tibial tuberosity.

Results

Compared with the knees in patients with normal hips, the femoral condyles in patients with dislocated hips were smaller and exhibited greater medial and lateral condylar asymmetry. The anterior femoral condylar angle of the femur was increased, as was the groove angle, while the trochlear groove was shallower in patients with dislocated hips. Furthermore, the lateral patella shift was reduced and the patellar tilt angle was increased in patients with dislocated hips compared with patients with normal hips. The extent of changes in these variables differed with the degree of dislocation. However, the posterior condylar angle of the femur was not affected by the degree of dislocation.

Conclusion

These findings suggest that developmental dysplasia of the hip is associated with morphological changes in the knee joint. These changes should be considered during hip and knee surgery.

Level of evidence

Prospective study, Level II.     

金属大头髋(ASRTM XL)的临床应用特点

目的 探讨金属大头髋(ASRTMXL)的临床应用特点.方法 对14例患者采用ASRTMXL金属大头髋进行全髋关节置换术(total hip arthroplasty,THA),其中强直性脊柱炎合并髋关节融合2髋,股骨头坏死3髋,继发性骨关节炎2髋,股骨颈骨折7髋.根据随访结果对金属大头髋的设计特点、临床特点进行分析.结果 本组患者术后1周开始扶拐行走,6周去拐行走,髋关节前屈、后伸、内旋、外旋、内收、外展显著改善,Harris评分术后平均90分(75～100分)、比术前平均30分(13～50分)显著提高.术后X线片示假体位置正确,外翻角、前倾角正常.无早期并发症发生.结论 金属大头髋早期随访效果好,假体设计具有磨损率低、活动范围大、脱位发生率低、臼杯变形小等特点.     

The Influence of Heterotopic Ossification on Functional Status of Hip Joint Following Total Hip Arthroplasty

Purpose: The functional failure induced by heterotopic ossification (HO) following total hip arthroplasty (THA) was analyzed and correlated to the radiologic failure.Patients and Methods: From July 1997 to July 2001, 315 patients (345 hips) received THA indicated by a hypertrophic osteoarthritis of higher degree (Kellgren grade III, IV). All patients were irradiated prophylactically for prevention of HO on the evening before surgery with a 7-Gy single fraction. The patients’ median age was 66.3 years. Radiologic failure was assessed by comparison of pre- and postoperative hip X-rays (immediately and 6 months after surgery). Analysis of radiographs was performed according to the Brooker Score. Clinical failure was appraised by measurement of passive range of motion (ROM) of the hip joint with a standard goniometer. The t-test was used for statistical analysis.Results: 281 patients (81.5%) did not develop HO. HO of Brooker grade I or II was found in 58 patients (16.8%). Six patients (1.7%) developed HO Brooker grade III or IV. There was a significant negative correlation between the degree of radiologic and clinical failure. ROM differed significantly between patients with HO Brooker grade 0, I, II and patients with HO Brooker grade III, IV. Comparing the pre- and postoperative ROM, all patients with Brooker grade 0, I and II showed a significant improvement of flexion, internal and external rotation, abduction and adduction movement. Patients with HO Brooker grade III and IV showed no improvement of ROM in the postoperative follow-up.Conclusion: The development of HO following THA influences the physical function of the hip joint dependent on the degree of ossification. HO of lower degree (Brooker I, II) does not influence the clinical outcome, whereas HO of higher degree (Brooker III, IV) reduces the function of hip arthroplasty. Therefore, the purpose of a prophylactic therapy must be to reduce HO of higher degree.     

Degeneration in dysplastic hips

Background Hip dysplasia is considered pre-osteoarthritic, causing degeneration in young individuals. Objective To determine the pattern of degenerative change in moderate to severely dysplastic hips in young patients. Design and patients One hundred and ninety-three consecutively-referred younger patients with hip pain believed to be caused by hip dysplasia constituted the study cohort. The average age was 35.5 years (range, 15–61 years). They were examined by close-cut transverse pelvic and knee computed tomography and antero-posterior radiographs (CT). We identified 197 hips with moderate to severe dysplasia, and 78 hips with normal morphology in the study cohort, whilst 111 hip joints were borderline dysplastic according to preset definitions. Comparative analyses of anatomy and distribution of degeneration between dysplastic and normal hips in the study cohort were performed. Results In dysplastic hips the anterior acetabular sector angle was significantly and inversely associated to femoral anteversion (p<0.001). The center-edge (CE) angle, the acetabular angle (AA), and the acetabular depth ratio (ADR) were significantly interrelated (p<0.001; correlation coefficients ranging from −0.8 to 0.7). Fifty-one hips were subluxated (24R/27L). There were no cases of complete dislocation. The formation of subchondral cysts or osteophytes in dysplastic hips was significantly associated with reduced minimum joint space width (p ranging from 0.005 to 0.02). However, in 67 hips with acetabular cysts, only 6 hips had minimum joint space widths =2.0 mm (8.9%) in the coronal plane. In 96 cases with acetabular cysts found in the sagittal plane, 43 cases had minimum joint space widths =2.0 mm (44.7%). Bony rim detachment at the site of labral insertion was recorded in 30 hips. Twenty-three of these were dysplastic (p=0.01). Conclusions Degeneration was most often found in the anterolateral part of the dysplastic hip joints. Most cysts were located above the transition zone between the bony and the fibrocartilaginous acetabulum, and we found a significantly- increased number of cases with avulsed bony fragments at the antero-lateral labral insertion in dysplastic hips compared to normal hips. It seems likely that the early degenerative process in dysplastic hips originates at the watershed zone between the acetabular labrum and the acetabular cartilage in response to subluxation and femoroacetabular impingement.