髂腰肌撞击——全髋关节置换术后并发症的诊治

目的分析全髋关节置换术后髂腰肌撞击假体引起疼痛原因及治疗措施。方法19例人工全髋关节置换术因髂腰肌撞击髋臼假体引起髋部疼痛患者,5例采用保守治疗无效后行髂腰肌肌腱切断术,12例行髂腰肌肌腱切断术,2例髋臼假体翻修。结果术后所有患者疼痛均明显减轻,Harris评分术前47～70（59±5．3）分,术后达83-95（92±1．7）分。双髋对比屈髋力量17例无明显下降,2例部分下降但并不影响髋关节功能。结论人工全髋关节置换术后因髂腰肌撞击髋臼假体引起髋部疼痛的患者,保守治疗常常效果不佳,而髂腰肌肌腱切断术效果较好。     

腰椎人工椎间盘置换术的研究进展

正退行性腰椎椎间盘疾病引起的腰痛(椎间盘源性腰痛)主要有非手术治疗或者责任节段椎间融合治疗两种方式[1]。但融合术后的假关节形成、邻近节段退变加剧等问题促使包括腰椎人工椎间盘置换术(TDR)在内的非融合手术技术迅速发展并成为腰椎融合术的备用选择[2、3]。相对椎间融合技术,腰椎人工椎间盘置换术在缓解症状的同时具     

双节段人工腰椎间盘置换术的疗效与探讨

[目的]观察采用以双段SB Charite Ⅲ人工椎间盘置换术治疗退变性腰椎间盘疾病的l临床结果并探讨其可行性。[方法]自2000年10月至2006年8月，对22例L4-S1退变的病例采用双节段人工腰椎间盘置换术，男16例，女6例；年龄43～54岁，平均48岁；均获得随访，随访时间10—61个月（平均37．4个月），分别于手术前后对患者的情况进行JOA评分和影像学对比。[结果]术后病例JOA评分较术前显著提高（P〈0．05）。按FRANKLE标准，JOA评分改善率1年后优12例，良7例，可3例；3年后共获得随访18例，其中优10例，良5例，可3例。术后X线片显示人工椎间盘位置正确，椎间隙高度恢复正常，椎间活动度得到维持。15例患者返回原工作，2例变换工作，1例退休。所有病例无假体功能并发症发生，无假体松动、半脱位、下沉。[结论]在严格适应证的前提下，双节段人工椎间盘置换术是可以获得满意临床疗效的，可在有条件的医院积极开展。     

Motion preservation following total lumbar disc replacement at the lumbosacral junction: a prospective long-term clinical and radiographic investigation

Background Context

Total lumbar disc replacement (TDR) intends to avoid fusion-related negative side effects by means of motion preservation. Despite their widespread use, the adequate quality and quantity of motion, as well as the correlation between radiographic data with the patient's clinical symptomatology, remains to be established. Long-term data are lacking in particular.

Analysis of a retrieved polyethylene total disc replacement component.

BACKGROUND CONTEXT: Although total disc replacements have been performed in Europe since the 1980s, this type of surgery is still new in the United States. The clinical performance of polyethylene in total disc replacements is still not well understood. PURPOSE: To describe the wear, surface damage, oxidation and mechanical properties in an explanted polyethylene total disc replacement component. STUDY DESIGN/SETTING: Case report, analysis of retrieved implant. PATIENT SAMPLE: Case report. OUTCOME MEASURES: Analysis of wear, oxidation and mechanical properties in the retrieved total disc replacement. METHODS: A 49-year-old female patient was implanted at L5-S1 with an SB Charite total disc prosthesis (DePuy Spine, Raynham, MA). After 1.6 years, the patient underwent a posterior, instrumented fusion because of intractable low back, left buttock and radicular left leg pain. Preoperative diagnostics revealed loosening at the bone implant interface at L5 and S1, anterior migration of the L5 base plate and severe degeneration of the L5-S1 facet joints. The retrieved polyethylene core showed evidence of damage around the periphery or rim. Transverse, subsurface cracks in the polyethylene, which initiated near the rim and penetrated into the interior of the component, were imaged using thin-film optical microscopy and micro-computed-tomography imaging. Analysis using Fourier transform infrared spectroscopy (American Society for Testing and Materials [ASTM] F2102) documented low levels of oxidation within 1 mm of the articulating surface. Miniature specimen mechanical testing (ASTM F2183), conducted near the surface where the oxidation was greatest, demonstrated that the mechanical properties were not substantially degraded. CONCLUSION: In this case, the anterior revision surgery was difficult and potentially life-threatening. The revision strategy of an instrumented posterior fusion to salvage a failed SB Charite disc replacement may be unpredictable and, in this case, ultimately unsuccessful. Despite the small size of the retrieved polyethylene core, ASTM standard test techniques developed for analysis of retrieved hip and knee replacements were readily adapted for the total disc prosthesis.     

The current status of lumbar total disc replacement

Total disc replacement is an exciting technology that may one day replace fusion as the gold standard treatment for DDD, but it is currently an experimental procedure in the United States. Promising short- and mid-term results have been reported for TDR, but longer follow-up and randomized trials comparing TDR to fusion and nonsurgical treatment are needed to fully define the role of TDR in the spine surgeon's armamentarium. Short-term complication rates have been acceptably low, but in the long term the durability of TDR implants and the vertebral endplate will provide challenges. Finally, it is essential that practitioners understand that a limited subset of patients are good candidates for TDR and that indiscriminate application of this technology will result in poor outcomes.     

The implications of constraint in lumbar total disc replacement

Lumbar total disc replacement (TDR) is an evolving technique that has the potential to replace arthrodesis as the gold standard surgical treatment of degenerative disc disease. The interaction between host anatomy and physiology and the biomechanical properties of TDR implants will determine the quality of long-term clinical results. However, there is scant literature addressing this subject. The purpose of this article is to discuss the implications of biomechanical constraint in TDR. Based upon available data for normal motion segments and the design of two TDRs currently in clinical trials, unconstrained designs appear to have a kinematic advantage. They are more likely to provide a physiologic mobile instantaneous axis of rotation (IAR), which may explain why they display greater range of motion in vivo. Their lack of constraint may prevent excessive facet joint or capsuloligamentous loads in the extremes of flexion and extension. Furthermore, since the IAR is mobile, they may be less sensitive to small errors in implant placement. On the other hand, constrained devices appear to have an advantage in protection of the posterior elements from shear loading. Spinal shear loads of considerable magnitude occur during activities of daily living. Whether the transference of stresses to the implant and implant-bone interface is clinically significant is unknown. Although this article focuses on two specific TDR designs, future designs will need to account for the same kinematic and loading concerns regarding constraint. We hope this discussion will assist clinicians and researchers in the design, selection, and clinical comparison of present and future TDR implants.     

Range of motion and adjacent level degeneration after lumbar total disc replacement.

BACKGROUND CONTEXT: There are no published studies on the relationship between total disc replacement (TDR) motion and the development of adjacent level degeneration (ALD). Because prevention of ALD is the underlying justification for TDR, studies investigating the validity of this concept are essential. PURPOSE: To examine the relationship between range of motion (ROM) and ALD 8.7 years after lumbar TDR. STUDY DESIGN/SETTING: Retrospective radiographic and chart review. PATIENT SAMPLE: Forty-two patients 8.7 years after lumbar TDR. OUTCOME MEASURES: Radiographic flexion-extension and ALD. Modified Stauffer-Coventry score. Oswestry Disability Questionnaire. Subjective patient ratings of back pain, leg pain, and disability. METHODS: We reviewed the flexion-extension radiographs of 42 patients 8.7 years after TDR. Cephalad adjacent levels were evaluated for degeneration: loss of disc space height, anterior osteophyte formation, or dynamic flexion-extension instability. Graphical analysis of motion and the prevalence of ALD was performed. A statistical relationship between ALD and clinical outcome was sought. RESULTS: Ten of 42 patients evaluated (24%) had radiographic ALD. The mean motion was 3.8 degrees +/-2.0 degrees. The patients with ALD had mean motion of 1.6 degrees +/-1.3 degrees whereas the patients without ALD had motion of 4.7 degrees +/-4.5 degrees (p=.035). A clear relationship between motion and the presence of ALD at 8.7-year follow-up was observed. Patients with motion 5 degrees or greater (n=13) had a 0% prevalence of ALD. Patients with motion less than 5 degrees (n=29) had a 34% prevalence of ALD (p=.021, odds ratio 13.5). ALD had no statistically significant effect on clinical outcome although the sample size was small. CONCLUSIONS: At 8.7-year follow-up, the prevalence of ALD after TDR is higher in patients with motion less than 5 degrees. The presence of ALD had no significant effect on clinical outcome, but the sample size was small. These data suggest that patients with significant ROM after lumbar TDR may have reduced risk for radiographic ALD.     

Anterior discectomy and total disc replacement for three patients with multiple recurrent lumbar disc herniations

Background context

Although results of primary discectomy are generally excellent with relief of leg pain, recurrent lumbar disc herniation is relatively common ranging from 5% to 25%. Patients with recurrent herniation may undergo revision surgery; however, this carries with it increased risks and lower success rates. Many surgeons will advocate a fusion in addition to repeat discectomy after the third recurrent herniated disc. With the approval of lumbar total disc arthroplasty, there now exists another option for the patient with three or more recurrent disc herniations to preserve motion, theoretically decrease the rate of adjacent-level disease, and ameliorate the patient’s symptoms.

Purpose

The purpose of this case report is to describe our experience using total disc replacement (TDR) in three patients after prior partial hemilaminectomy and discectomy for the treatment of a third and fourth recurrent lumbar disc herniation.

Study design

This article is a report of three cases from a spine specialty center describing an alternative surgical technique for patients with multiple recurrent lumbar disc herniation.

Methods

Comprehensive chart review of three patients with recurrent lumbar herniation who underwent TDR.

Results

Anterior discectomy and TDR were undertaken, and at most recent follow-up (8–12 months), all patients had improvement of their visual analog scale and Oswestry Disability Index. No patient had postoperative complications or reoperation.

Conclusions

Recurrent disc herniation is a relatively common problem that may be difficult to treat. Traditionally, a patient presenting with three or more recurrent disc herniation may likely have undergone revision discectomy with fusion. The current case report suggests that TDR may be an alternative option in select patients.     

Measurement of total disc replacement radiographic range of motion: a comparison of two techniques

OBJECTIVE: Current methods used to measure total disc replacement (TDR) radiographic range of motion (ROM) have not been previously evaluated. Sagittal ROM is measured by determining the change in the Cobb angle of the prosthesis from the flexion to the extension radiographs. Either the metallic endplates or the keels of the TDR prosthesis can be used as radiographic landmarks in measuring ROM. We hypothesized that use of the prosthesis keels as radiographic landmarks, when compared with the use of prosthesis endplates, might lead to more precise measurements of TDR sagittal ROM. METHODS: Two observers (a fifth-year orthopedics resident and an attending orthopedic spine surgeon) measured the ROM of 51 Prodisc II TDRs on standard flexion and extension lumbar spine radiograph sets. Repeated measurements were made on two occasions using either the keels or the endplates as landmarks. Precision was defined as the mean of the absolute differences between measurements. RESULTS: For observer A, the mean absolute difference between two measurements was 1.4 degrees with the keel method compared with 3.0 degrees with the endplate method (P < 0.001). For observer B, the mean absolute difference between two measurements was 1.8 degrees with the keel method and 3.3 degrees with the endplate method (P < 0.001). When the interobserver differences were examined, the mean absolute difference was 1.8 degrees with the keel method and 3.3 degrees with the endplate method (P < 0.001). CONCLUSIONS: Our results show that the use of TDR prosthesis keels as radiographic landmarks, when compared with the use of prosthesis endplates, yields greater precision in ROM measurement. For TDR prostheses with a keel, we recommend using the keel to measure ROM.     

腰椎Active-L人工椎间盘置换术与腰椎融合术的临床比较研究

背景：腰椎融合术一直被广大学者认为是治疗腰椎间盘退行性病变的“金标准”,但文献报道腰椎融合术加速相邻节段退变的发生,为保留脊柱功能单位的生理和运动特性,提出人工椎间盘置换术。目的：比较前路Active．L型人工椎间盘假体置换术和后路腰椎融合术治疗单节段腰椎间盘退行性病变患者的疗效和安全性。方法：2009年1月至2010年4月62例因腰椎间盘退行性病变的手术患者,根据手术方式分为试验组和对照组。试验组行腰椎人工椎间盘置换术患者20例,男10例,女10例;年龄36-58岁,平均47．7岁;术前诊断：腰椎间盘突出症16例,腰椎间盘源性下腰痛4例,腰椎间盘后路开窗术后复发1例;手术节段：13-42例,L4-513例,L5-S15例。对照组行腰椎融合术患者42例,男22例,女20例;年龄40-60岁,平均48．5岁;术前诊断：腰椎间盘突出症32例,腰椎间盘源性下腰痛7例,腰椎间盘后路开窗术后复发3例;手术节段：13-44例,L4-526例,15-S112例。随访观察指标包括：（1）临床疗效评定：术后疼痛及功能改善率的评定;手术成功率的评定。（2）影像学评定：腰椎前凸角和手术节段的椎问活动度独立因素t检验进行对比评价。结果：全部获得随访,试验组随访时间为12-27个月,平均19．3个月;对照组随访时间为12-27个月,平均19．8个月。两组患者在治疗下腰痛方面均取得明显疗效。在改善ODI功能评分、VAS疼痛评分、SF-36、椎间隙活动度上,试验组优于对照组,两组间比较有显著性差异（P〈0．05）;在恢复腰椎前凸序列上,两组间无显著性差异（P〉0．05）;两组均未出现严重并发症。结论：人工椎间盘置换术和融合术均取得良好的临床效果,但人工椎间盘置换术在掌握严格的手术适应证和禁忌证的条件下,相比腰椎融合术具有更好的临床疗效并保留病变节段的活动度。因此,在合适的手术适应证下,人工间盘置换术是一种更优且可以替代腰椎融合术的有效治疗方法。     

Mid- to long-term results of total disc replacement for lumbar degenerative disc disease: a systematic review

Background

Lumbar total disc replacement (TDR) has shown satisfactory clinical outcomes with few complications and reoperations at short-term follow-up, but the mid- to long-term results are not clear.

Purpose

The objective of this study was to evaluate the mid- to long-term clinical outcomes of artificial TDR for lumbar degenerative disc diseases.

Patients and methods

A systematic search was conducted using the PubMed database to identify studies of TDR surgery that included at least 3?years of follow-up. The search keywords were as follows: lumbar, total disc replacement, and arthroplasty. The following data were extracted: patient demographics, visual analogue scale (VAS) and Oswestry disability index (ODI) scores, satisfactory rate, clinical success rate, complications, and reoperations.

Results

Thirteen studies, including eight prospective studies and five retrospective studies, met the criteria. A total of 946 patients were identified who reported at least 3?years of follow-up results. The artificial prostheses in these studies were ProDisc-L, Charité, AcroFlex, Maverick, and XL TDR. Patients with lumbar TDR demonstrated significant improvements in VAS scores of 51.1 to 70.5% and of ??15.6 to ??44.4 for Oswestry disability index (ODI) scores at the last follow-up. Patient satisfaction rates were reported in eight studies and ranged from 75.5 to 93.3%. Complication rates were reported in 11 studies, ranging from 0 to 34.4%. The overall reoperation rate was 12.1% (119/986), ranging from 0 to 39.3%, with eight of the 13 studies reporting a reoperation rate of less than 10%.

Conclusions

This review shows that lumbar TDR effectively results in pain relief and an improvement in quality of life at mid- to long-term follow-up. Complication and reoperation rates were acceptable. However, this study did not provide sufficient evidence to show that lumbar TDR is superior to fusion surgery. To answer that question, a greater number of high-quality randomized controlled trials (RCTs) are needed.

     

Prevalence of lumbar total disc replacement candidates in a community-based spinal surgery practice

STUDY DESIGN: This study was a retrospective record review of consecutive lumbar surgical patients seen by one surgeon in a private, community setting over a 15-month period. OBJECTIVE: The purpose of this study was to evaluate the potential frequency that candidates for total disc replacement (TDR) might be seen in a community-based spinal surgery practice. SUMMARY OF BACKGROUND DATA: The impact of TDR technology on the practice of spine surgery remains uncertain. The only previous report in the literature evaluating prevalence of contraindications to TDR reflected a patient cohort from a high volume, academic, tertiary referral center, and may not accurately reflect the experiences of the "average" spine surgeon, in community practice. Further, this study did not assess the prevalence of patients who possessed an indication for TDR. METHODS: We performed a retrospective chart review of consecutive patients who underwent lumbar spine surgery between 2003 and 2004 (during which period the senior author was in a community-based private practice). Particular attention was paid to conditions considered to be contraindications to TDR. The patients were divided into nonfusion and fusion subgroups. The percentage of patients with exclusion criteria was calculated in each group, as was the percentage of potential TDR candidates. RESULTS: A total of 190 patients were identified: 124 had nonfusion procedures and 66 had fusion procedures. In the nonfusion group, all patients had at least 1 contraindication to TDR. In the fusion group, 86% of the patients had at least 1 contraindication to TDR. Of those fusion patients with degenerative disc disease, 33% had no contraindication to TDR, and were considered potential candidates for TDR. Seventeen percent of all fusion patients had Worker's Compensation Insurance; among those patients considered to be potential TDR candidates, 44% had Worker's Compensation Insurance, and a further 22% of TDR candidates were on permanent disability (Medicare) as a result of a work-related injury. CONCLUSIONS: This study suggests that in a community-based spinal surgery practice setting, only 14% of fusion patients, and only 5% of all lumbar surgery patients, would be TDR candidates. Furthermore, of those potential TDR candidates, as many as 66% might be expected to have their underlying condition related to a claim of a compensable work-related injury.