肩关节置换术中肱骨假体低置的疗效分析

目的探讨肱骨假体低置在肩关节置换术患者中的疗效。方法对12例肱骨近端三、四部骨折的老年患者行半肩关节置换术治疗,术中采用假体低置使肱骨大结节与肱骨近端重叠方式固定,并对其进行5～36个月随访,参照美国肩肘关节医师学会肩关节评分系统（ASES）进行功能评分。结果 12例患者均无明显疼痛,无肩关节脱位或不稳的情况出现,患肩上举、内旋、外旋、外展活动总体满意。ASES功能评分平均为81分,评定为满意。结论肱骨假体低置对肩关节置换术患者的早期功能及稳定性影响不大。     

肩胛带骨肿瘤的外科治疗结果及评价

目的 探讨肩胛带骨肿瘤的手术切除方式、重建方法,观察术后功能恢复情况及临床结果.方法 回顾性分析1998年7月至2006年7月收治的71例肩胛骨周围骨肿瘤患者的病例资料,其中恶性肿瘤61例,骨巨细胞瘤10例.15例恶性肿瘤起源于肩胛骨,56例起源于肱骨近端.男42例,女29例;年龄11～62岁,平均36.5岁.手术方法:肩胛带离断术10例,单纯肩胛骨切除3例,肩胛骨切除、人工肩胛骨置换3例,部分肩胛骨及肱骨近端切除、假体置换8例,肱骨近端切除、假体置换47例.结果 10例骨巨细胞瘤患者肩周肌肉保留较好,术后MSTS功能评分平均28分.起源于肱骨近端的原发恶性骨肿瘤患者三角肌止点处均予以切除,术后肩外展30°～60°,MSTS功能评分平均23分.37例肱骨骨肉瘤患者中4例(10.8%)局部复发,2例骨转移,5例肺转移.7例转移患者均死亡.1例恶性骨巨细胞瘤患者出现肺转移死亡.3例尤文肉瘤患者出现肺转移死亡.5例肱骨及5例肩胛骨软骨肉瘤患者术后未见局部复发及转移.结论 肩胛带骨肿瘤切除、人工肱骨近端假体重建能保留完整肘部及手部功能、并发症少,是肩部恶性肿瘤的首选术式;肱骨近端骨肉瘤和下肢骨肉瘤比较预后较好;肱骨近端恶性肿瘤行关节内肿瘤切除和关节外肿瘤切除肿瘤的局部复发率接近,提示对多数肱骨近端恶性肿瘤可以采用关节内切除.     

Current status and perspectives of shoulder replacement

Summary Basis of the modern shoulder implants is the Neer II-system, a non constrained total shoulder prosthesis with conforming radii of curvature and improved protection against dislocation. The second generation of shoulder prosthesis is based on the geometric shaft design of the Neer II prosthesis and offers not only a variety of modular head- and shaft-sizes but also through different radii a physiologic rotation-translation-mechanism. The third generation of humeral head prosthesis carries the concept of an anatomic reconstruction one step further and enables the surgeon to adjust the inclination and the eccentric offset of the humeral head to restore the centre of rotation. The latest development in shoulder arthroplasty are humeral head prosthesis with a fully variable 3-dimensional modularity to independently adjust the prosthestic head position regardless of the individual shaft geometry. This achieves a 3-dimensional adaptability of the prosthetic head about the stem axis in the coronary and in the sagittal plane. Besides of the humeral shaft prosthesis an alternative concept of shoulder joint replacement is established – the replacement of the humeral head articular surface. A hemispheric surface prosthesis – cup arthroplasty – is cemented onto the residual humeral head, which eliminates the obligatory humeral head resection and the reaming of the medullary canal. Bipolar shoulder prosthesis are humeral shaft prosthesis with a bi-rotational head system. Their indication is limited to pre-existing lesions of the rotator cuff and/or the glenoid surface. The inverse total shoulder prosthesis reverses the articular surface morphology of the humeral head and the glenoid. The hemispheric glenoid component serves as the centre of rotation for the concave epiphyseal proximal humerus component. This implant is especially used in cases of massive rotator cuff deficiences. The role of shoulder prosthesis in treating acute humeral head fractures needs special consideration. A fracture prosthesis has to restore the exact length of the humerus, the centre of rotation, and the anatomical retroversion. Positioning of the tubercula and their adequate osteosynthesis is most critical and fundamental to ensure a correct healing process. A failed consolidation of the tubercula does not lead to a satisfying result. The shoulder joint replacement can be sufficiently fixated in cemented, cementless or hybrid techniques. Today several component design variations of cemented glenoid implants exist. Their main distinction is the fixation system which can be divided into two main groups – the keel – and the peg-shaped glenoid components. The peg-shaped anchorage system shall guarantee a greater stability against shear-forces. Cementless glenoid components consist of a polyethylen inlay and a surface treated metal-back with an integrated fixation system. These fixation systems are object of intensive biomechanical research and range from conventional screw fixation to specialised cone systems and self-cutting cage-screw-systems. The critical area of cementless glenoid components is the transition zone of the PE-inlay and the metal-back because of high force development. The question of implanting a hemi- or total shoulder prosthesis is answered by the morphologic changes of the glenoid articular surface, which includes the size of the subchondral defect and the underlying etiology of the shoulder joint disease, and the age of the patient. Preoperative planning must consist of an adequate radiologic work-up – X-ray, CT or MRI – to accurately assess the glenoid morphology. G. Walch categorised the different glenoid lesions and developed a very important classification of possible glenoid deformations. To compare and evaluate the operative results one must consider the different shoulder prosthesis and the discrepancies between a hemi- and a total shoulder prosthetic replacement. Looking at the loosening and survival rate of the implant the results are related to the type of prosthesis and the preoperative diagnosis. The Neer total shoulder prosthesis has a 15 year survival rate of 87 %, compared to 74 % of the hemi-prosthesis. The objective for the future has to be to further advance the development of prosthetic components, especially for primary joint replacement in acute humeral head fractures. Another point of interest is how to reduce the still existing high loosening rates of the glenoid components. A fairly new research-field is the computer-assisted surgery, e. g. navigation systems and robotics. The computer-assisted navigation could be of great advantage to accurately find the individual resection plane (inclination and restroversion) of the humeral head. The use of a surgery-robot could be very helpful to reproducibly achieve the desired conformity of the articular surface when preparing the glenoid.      

Functional recovery after a reverse prosthesis for reconstruction of the proximal humerus in tumor surgery

An alternative treatment for primary bone tumors of the proximal humerus was assessed. Four patients, who made full functional recovery after complete resection of the proximal humerus inclusive of the rotator cuff and subsequent reconstruction with a reverse shoulder prosthesis, were examined clinically and radiographically. Distinct medialization of the center of rotation of the glenohumeral joint (28 mm) and elongation of the remaining deltoid muscle (116%) were measured. Increased scapular rotation (118%) was observed. The radiologic results and thoracoscapular rhythm analyses were implemented in a three-dimensional computerized model of the glenohumeral joint. This allowed us to calculate a doubling of the moment of the deltoid abductor muscle in the true scapular plane. After tumor surgery, in which the proximal humerus is resected without reinserting the rotator cuff, full functional recovery of the shoulder can be obtained with a total shoulder prosthesis, medializing the glenohumeral center of rotation and elongating the remaining deltoid muscle. Level of Evidence: Therapeutic study, Level IV (case series-no, or historical control group).     

A humeral modular prostheses for bone tumour surgery: a study of 56 cases

Summary Fifty six humeral prostheses were inserted from 1974 to 1984 for primary bone tumours of the shoulder. In 40 patients a proximal humeral resection was performed and in the remaining 16 cases a Tikhoff-Linberg procedure was employed. The length of humeral resection ranged from 9 cm to 24 cm. A detailed analysis of the oncological and functional results was made. The resection was well clear in 42 patients (75%), marginal in 12 (21.5%), and through tumour in 2 (3.5%). Eight local recurrences were noted. The functional results were satisfactory, the patients having a wide range of active rotation and being able to do sedentary work.A new modified humeral modular prosthesis was introduced in 1984 and is presented.Supported by a grant from the National Council for Research No. 84.00623.44.     

Current status and perspectives of shoulder replacement

Basis of the modern shoulder implants is the Neer II-system, a non constrained total shoulder prosthesis with conforming radii of curvature and improved protection against dislocation. The second generation of shoulder prosthesis is based on the geometric shaft design of the Neer II prosthesis and offers not only a variety of modular head- and shaft-sizes but also through different radii a physiologic rotation-translation-mechanism. The third generation of humeral head prosthesis carries the concept of an anatomic reconstruction one step further and enables the surgeon to adjust the inclination and the eccentric offset of the humeral head to restore the centre of rotation. The latest development in shoulder arthroplasty are humeral head prosthesis with a fully variable 3-dimensional modularity to independently adjust the prosthestic head position regardless of the individual shaft geometry. This achieves a 3-dimensional adaptability of the prosthetic head about the stem axis in the coronary and in the sagittal plane. Besides of the humeral shaft prosthesis an alternative concept of shoulder joint replacement is established – the replacement of the humeral head articular surface. A hemispheric surface prosthesis – cup arthroplasty – is cemented onto the residual humeral head, which eliminates the obligatory humeral head resection and the reaming of the medullary canal. Bipolar shoulder prosthesis are humeral shaft prosthesis with a bi-rotational head system. Their indication is limited to pre-existing lesions of the rotator cuff and/or the glenoid surface. The inverse total shoulder prosthesis reverses the articular surface morphology of the humeral head and the glenoid. The hemispheric glenoid component serves as the centre of rotation for the concave epiphyseal proximal humerus component. This implant is especially used in cases of massive rotator cuff deficiences. The role of shoulder prosthesis in treating acute humeral head fractures needs special consideration. A fracture prosthesis has to restore the exact length of the humerus, the centre of rotation, and the anatomical retroversion. Positioning of the tubercula and their adequate osteosynthesis is most critical and fundamental to ensure a correct healing process. A failed consolidation of the tubercula does not lead to a satisfying result. The shoulder joint replacement can be sufficiently fixated in cemented, cementless or hybrid techniques. Today several component design variations of cemented glenoid implants exist. Their main distinction is the fixation system which can be divided into two main groups – the keel – and the peg-shaped glenoid components. The peg-shaped anchorage system shall guarantee a greater stability against shear-forces. Cementless glenoid components consist of a polyethylen inlay and a surface treated metal-back with an integrated fixation system. These fixation systems are object of intensive biomechanical research and range from conventional screw fixation to specialised cone systems and self-cutting cage-screw-systems. The critical area of cementless glenoid components is the transition zone of the PE-inlay and the metal-back because of high force development. The question of implanting a hemi- or total shoulder prosthesis is answered by the morphologic changes of the glenoid articular surface, which includes the size of the subchondral defect and the underlying etiology of the shoulder joint disease, and the age of the patient. Preoperative planning must consist of an adequate radiologic work-up – X-ray, CT or MRI – to accurately assess the glenoid morphology. G. Walch categorised the different glenoid lesions and developed a very important classification of possible glenoid deformations. To compare and evaluate the operative results one must consider the different shoulder prosthesis and the discrepancies between a hemi- and a total shoulder prosthetic replacement. Looking at the loosening and survival rate of the implant the results are related to the type of prosthesis and the preoperative diagnosis. The Neer total shoulder prosthesis has a 15 year survival rate of 87 %, compared to 74 % of the hemi-prosthesis. The objective for the future has to be to further advance the development of prosthetic components, especially for primary joint replacement in acute humeral head fractures. Another point of interest is how to reduce the still existing high loosening rates of the glenoid components. A fairly new research-field is the computer-assisted surgery, e. g. navigation systems and robotics. The computer-assisted navigation could be of great advantage to accurately find the individual resection plane (inclination and restroversion) of the humeral head. The use of a surgery-robot could be very helpful to reproducibly achieve the desired conformity of the articular surface when preparing the glenoid.     

肩关节肿瘤切除和重建后的患肢功能观察

目的 肩关节肿瘤切除后,探讨不同重建方式的患肢长期功能。方法回顾性分析32例肩关节肿瘤保肢患者的临床资料。重建方式包括：8例一期肩关节融合,7例假体异体骨复合物,6例功能性间隔物,5例未行重建或悬吊术,3例假体,2例带血管蒂腓骨和1例异体骨。结果23例生存患者平均随访81个月。不同重建方式的功能评分分别为：一期肩关节融合为87％,主动运动优良,肩部有力;假体异体骨复合物为79％,间隔物为66％,未重建为85％,假体为60％和带血管蒂腓骨为73％。结论肩关节肿瘤的重建方式是根据切除范围和患者的实际需要来选择。如外展肌群无法重建,肩关节融合的功能良好,肩部有力;如果外展肌群可以重建,假体异体骨复合物功能较好。     

Geometric analysis of commonly used prosthetic systems for proximal humeral replacement.

BACKGROUND: The anatomy of the proximal part of the humerus is extremely variable. The extent to which existing prosthetic systems and operative technique allow replication of this variability has not been established. METHODS: Four commonly used press-fit prosthetic systems for shoulder arthroplasty were compared with respect to their ability to match the superior-inferior and medial-lateral dimensions of the articular surface in twenty-one cadaveric humeri. The comparisons were accomplished with a computer optimization algorithm that searched a database of prosthetic geometry and selected the best match to the original anatomy. The algorithm assumed an osteotomy of the humeral head at an angle equivalent to the stem-head angle of the prosthesis, without violation of the greater tuberosity or the metaphyseal bone. The best match was defined as the prosthetic combination (stem and head) that least displaced the center of rotation and the articular surface, with both factors weighted equally. RESULTS: None of the prosthetic systems that were evaluated allowed identical replication of the articular surface. Rather, they displaced the center of rotation a mean of 14.7 millimeters (range, 3.3 to 31.4 millimeters) from its original position. To reach this minimized displacement, the prosthetic combinations that were selected by the algorithm also resulted in a mean diminution of the arc of the articular surface (a smaller head size) of 26 degrees (range, 11 to 41 degrees). In every instance, the selected prosthesis imposed a superior and lateral shift of the center of rotation that in effect shifted a smaller prosthetic humeral head up the slope of the humeral osteotomy. CONCLUSIONS: Press-fit prosthetic systems for shoulder arthroplasty that are commonly used necessitate marked alterations of the original anatomy. To the extent that a shoulder arthroplasty is an attempt to reproduce the normal anatomy, these findings have profound implications for operative technique and future prosthetic design. CLINICAL RELEVANCE: We believe that the superior position of the prosthetic head predicted by the present study plays a role in late complications of shoulder arthroplasty, such as rotator cuff tendinopathy, superior humeral migration, and loosening of the glenoid component.     

Reconstruction of the proximal humerus after wide resection of tumours

In 45 patients we assessed the functional results and complications for three different reconstructive procedures after resection of primary tumours of the proximal humerus. An osteoarticular allograft was used in 11, a clavicula pro humero operation in 15 and a tumour prosthesis in 19. The glenoid was resected with the proximal humerus in 25 patients. The axillary nerve was resected in 42 patients. The complication rate was lowest after reconstruction with a tumour prosthesis. The clavicula pro humero operation resulted in the most revisions. Cumulative survival rates for all the reconstructive procedures were similar. At follow-up at two years the functional results for the three reconstructive procedures were the same with a mean functional rating of 79% (Musculoskeletal Tumor Society). Excision of the glenoid had no influence on the functional result. Our findings indicate that the use of a tumour prosthesis is the most reliable limb-salvage procedure for the proximal humerus. The clavicula pro humero is an appropriate procedure if a prosthesis cannot be used.     

Functional outcomes and complications of reconstruction of the proximal humerus after intra‐articular tumor resection

Objective: To evaluate functional outcomes and complications of reconstruction of the proximal humerus after intra‐articular tumor resection. Methods: Twenty‐five patients who underwent Malawer I type resection and reconstruction of the proximal humerus for treatment of malignant or invasive benign tumors from August 1999 to August 2005 were evaluated. A variety of reconstructive procedures, including modular tumor prosthesis, osteoarticular allograft, and allograft‐prosthetic composite (APC), were performed after resection of tumor. Oncological and radiographic parameters were evaluated. The modified Musculoskeletal Tumor Society (MSTS) evaluation system was used to assess limb functional outcome. Results: The study group consisted of 10 male and 15 female patients, among which there were 20 malignant and 5 benign tumors. Restoration of shoulder function was achieved with a prosthesis in 6 patients, osteoarticular allograft in 12, and allograft‐prosthesis composite in 7. At a mean of 48 months follow‐up, 2 patients had died of disease. Two patients had local recurrence and 2 had metastatic disease. On the basis of the modified MSTS functional evaluation, the mean scores were 22.50 in the modular prosthesis group, 24.58 in the osteoarticular allograft group, and 27.00 in APC group, respectively. Joint instability and subluxation were serious complications affecting shoulder function in 10 patients. Conclusion: Reconstruction of the proximal humerus is an option that provides good relief of pain and preserves manual dexterity. Functional outcomes are better for APC and allograft than for modular prosthesis, due to retention of the rotation cuff. Complications in the APC group were less than in the allograft one.     

Prosthetic component relationship of the reverse Delta III total shoulder prosthesis in the transverse plane of the body

The Delta III (DePuy International Ltd, Leeds, UK) reverse total shoulder prosthesis has provided a successful functional outcome in cuff tear arthropathy (CTA); however, internal and external rotation remain compromised. Positioning of the prosthetic components in the transverse plane has theoretically been suggested to affect rotation. Twenty-seven patients who received a Delta III reversed total shoulder prosthesis for CTA were analyzed (mean follow-up, 43 months) using standard radiographs and computed tomography. The position of the prosthetic components and the possible influence of scapular rotation was analyzed using a uniform spatial reference system using axes in reference to the sagittal or coronal plane. We assessed impingement of the humeral component on the glenoid neck in neutral and internal rotation. An increase in the anterior divergence of the glenoid and humeral prosthetic components correlates with an increase in radiologically measured internal rotation (r = 0.932, P < .001). The uniformity of the reference system used seems to allow accurate positioning of the components intraoperatively and can be useful for analysis of the prosthetic component relationship postoperatively.     

Proximal humeral head fractures--Future development of shoulderimplants

In 1951 a shoulder prosthesis was developed for the treatment of complex humeral head fractures by Neer. The Neer-II-Prosthesis, which was developed further in 1973 represents the basis of modern shoulder implants. The unsatisfactory postoperative functional results for primary humeral head replacement required the development of new adaptable implants for the treatment of complex humeral fractures, which allow the reconstruction of humeral length, the reconstruction of center of rotation and humeral offset, the anatomic positioning, the reconstruction of retrotorsion and the secure refixation of the tuberosities. The development of third and fourth generation of humeral head prosthesis achieves a three-dimensional adaptability for the conditions of posttraumatic arthritis. Primary and secondary humeral head replacement in humeral head fractures as well as revision of prosthetic replacement are complex and technical demanding operations with high and different requirements on implants having to be realised on further development.     

Influence of humeral prosthesis height on biomechanics of glenohumeral abduction. An in vitro study

BACKGROUND: During shoulder replacement surgery, the normal height of the proximal part of the humerus relative to the tuberosities frequently is not restored because of differences in prosthetic geometry or problems with surgical technique. The purpose of the present study was to determine the effect of humeral prosthesis height on range of motion and on the moment arms of the rotator cuff muscles during glenohumeral abduction. METHODS: Tendon excursions and abduction angles were recorded simultaneously in six cadaveric specimens during passive glenohumeral abduction in the scapular plane. Moment arms were calculated for each muscle by computing the slope of the tendon excursion-versus-glenohumeral abduction angle relationship. The experiments were carried out with the intact joint and after replacement of the humeral head with a prosthesis that was inserted in an anatomically correct position as well as 5 and 10 mm too high. RESULTS: Insertion of the prosthesis in positions that were 5 and 10 mm too high resulted in significant and marked reductions of the maximum abduction angle of 10 degrees (range, 5 degrees to 18 degrees ) and 16 degrees (range, 12 degrees to 20 degrees ), respectively. In addition, the moment arms of the infraspinatus and subscapularis decreased by 4 to 10 mm. This corresponded to a 20% to 50% decrease of the abduction moment arms of the infraspinatus and an approximately 50% to 100% decrease of the abduction moment arms of the subscapularis, depending on the abduction angle and the part of the muscle being considered. CONCLUSIONS: If a humeral head prosthesis is placed too high relative to the tuberosities, shoulder function is impaired by two potential mechanisms: (1) the inferior capsule becomes tight at lower abduction angles and limits abduction, and (2) the center of rotation is displaced upward in relation to the line of action of the rotator cuff muscles, resulting in smaller moment arms and decreased abduction moments of the respective muscles. Clinical Relevance: In patients managed with shoulder replacement surgery, limitation of range of motion, loss of abduction strength, and overload with long-term failure of the supraspinatus tendon are potential consequences of positioning the humeral head of the prosthesis proximal to the anatomic position.     

Evaluation of a reconstruction reverse shoulder for tumour surgery and tribological comparision with an anatomical shoulder arthroplasty

Purpose

The functional results after reconstruction of the proximal humerus in tumour surgery are poor. Therefore, a reversed proximal humerus replacement was developed in our institution (MUTARS humerus inverse). A low degree of wear on the polyethylene is required because of the patients’ youth and demands on shoulder function. A special type of polyethylene with shock-absorbing properties has been developed to minimise polyethylene wear in the MUTARS inverse proximal humerus replacement. We compared the tribological properties of an anatomical shoulder prosthesis (CAPICA) with the new reversed proximal humerus replacement (MUTARS humerus inverse).

Methods

Both prostheses were tested up to 5 × 10⁶ cycles. Every millionth cycle the surface was inspected and a gravimetric measurement was performed. A measurement of surface roughness was done before testing and after 5 × 10⁶ cycles.

Results

In both prostheses after 5 × 10⁶ cycles there were no major defects, such as delamination, observed. In the reversed proximal humerus replacement abrasion of 28 mg/10⁶ cycles was detected. The mean abrasion of the anatomical prosthesis was 9.28 mg/ 10⁶ cycles.

Conclusion

The glenoid component of the first reversed humerus replacement (MUTARS humerus inverse) has wear properties comparable to those of normal reversed shoulder prostheses. This is important, as this type of prosthesis is used in young patients after resection of bone tumours, with a good functional outcome. It can, therefore, be expected that the revision rate due to wear will be as high as in patients with normal reversed shoulder prostheses.     

半肩关节置换术治疗肱骨近端严重病损

目的:采用半肩关节置换术治疗肱骨近端严重病损,并评定疗效。方法:共36例。19例成人肱骨近端四分骨折。9例肱骨近端低恶性度骨肿瘤,肱骨头坏死8例。均采用骨水泥固定人工肱骨头置换术治疗。术后功能锻炼。定期X线检查,评估假体稳定性和肩关节功能。随访时间为1～8年,平均5年3个月。结果:1例42岁肱骨近端骨肿瘤患者术后2年出现松动;3例肱骨近端四分骨折患者伴有肩关节外旋部分受限和轻度疼痛。其余病例无痛,无松动,肩关节功能满意。结论:与远期结果有关的因素包括准确的手术适应证的选择,正确的手术方法特别是修复骨缺损和肩袖损伤;选择好假体的大小和厚度以及假体安放位置;另一关键因素为合理的功能锻炼。     

Hemi-replacement arthroplasty of the proximal humerus. A case report

A ten-year-old girl underwent excision of a chondrosarcoma of the right proximal humerus with subsequent insertion of a prosthesis. Failure of the device occurred six years after operation, requiring revision to an identical but shorter prosthesis. This device failed 1 1/2 years later and was replaced by a fibular graft inserted in the humeral medullary canal. The fibular graft was removed 18 months later, resulting in a flail right shoulder. The mode of failure in each instance was anterior and superior dislocation of the hemiarthroplasties. Currently, ten years after the initial procedure, the patient is tumor free with a shortened functional right upper extremity.     

The Tikhoff-Linberg procedure: report of ten patients and presentation of a modified technique for tumors of the proximal humerus

The Tikhoff-Linberg resection is a limb-sparing surgical option to be considered for bony and soft-tissue tumors in and around the proximal humerus and shoulder girdle. Careful selection of patients whose tumor does not involve the neurovascular bundle in the axilla is required. The distal clavicle, upper humerus, and part or all of the scapula are resected. The tumor remains covered by the deltoid muscle plus portions of the muscles that arise from or insert into the resected specimen. In patients with tumors of the proximal humerus a custom prosthesis is used to maintain length and stabilize the distal humerus. Elbow flexion plus stability of the shoulder without the need of an orthosis may be achieved with muscle transfers. Function of the hand and forearm after Tikhoff-Linberg resection should be near normal. Review of results in 10 patients shows no local recurrences and excellent function. The major postoperative problem was nerve palsy. The Tikhoff-Linberg procedure should continue to be used for limb salvage in selected patients with tumors in or around the shoulder girdle.     

定制型肱骨近端假体结合人工补片重建肩关节的疗效分析

目的 探讨肱骨近端骨肿瘤保肢术中使用人工补片重建盂肱关节囊的手术方法及其对稳定肩关节、预防术后肱骨头脱位的效果.方法 2006年2月至2009年1月,回顾性分析接受定制型肱骨近端假体结合聚丙烯非降解性人工补片重建肩关节的患者12例,男7例,女5例;年龄21～55岁,平均38岁.肿瘤类型:骨巨细胞瘤9例,骨肉瘤1例,软骨肉瘤2例.9例骨巨细胞瘤患者中3例为Campanacci Ⅱ期,6例为Campanacci Ⅲ期;1例骨肉瘤患者为Enneking ⅡB期;2例软骨肉瘤患者均为Enneking Ⅱ A期.采用国际骨与软组织肿瘤协会(MSTS)功能评估标准评价术后肩关节功能.结果 患者均获得随访,随访时间24～52个月,平均35个月.手术出血量150～500 ml,平均254 ml;手术时间150～200 min,平均172 min.术后患者肩关节前屈20°～60°,平均41°;外展20°～70°,平均42°.MSTS评分为53%～77%,平均66%.术后无一例患者出现臂丛损伤、切口感染及假体脱位;随访期间无一例患者出现局部复发、远处转移或死亡.结论 使用聚丙烯非降解性人工补片重建盂肱关节囊可显著减少肱骨近端骨肿瘤保肢术后肱骨头假体脱位的发生,便于周围软组织的附着和长入.

Abstract：

Objective To investigate the surgical technique,postoperative function and dislocation incidence of proximal humerus reconstruction with metallic endoprostheses and polypropylene knitted nonabsorbable mesh after proximal humeral tumor resection.Methods Twenty patients with proximal humeral tumor were retrospectively reviewed.They were performed proximal humerus reconstruction with proximal humeral prosthesis and polypropylene knitted non-absorbable mesh from February 2006 to January 2009.There were 5 women and 7 men with a mean age of 38 years(range,21-55 years)at the time of surgery,and giant cell tumor in 9 patients(including Campanacci Ⅱ for 3,Campanacci Ⅲ for 6),osteosarcoma in 1(Enneking ⅡB).and chondrosarcoma in 2 (Enneking ⅡA).The operative time,blood loss,and shoulder movement postoperation were analysed.According to the assessment system by MSTS,the function of limb after surgery was assessed.Results Patients were followed clinically and radiographically for a minimum of 24 months (mean,35 months;range,24-52 months).The mean operative time was 172 min(range,150-200min).The mean blood loss was 254 ml (range,150-500 ml).There were no shoulder dislocations at final follow-up.The mean shoulder flexion was 41°(range,20°-60°)and mean shoulder abduction was 42°(range,20°-70°).The mean postoperative functional assessment score of the limb was 66%(range,53%-77%).None of the Datients had a wound infection,traction neuropraxia or died after the surgical procedure.Conclnsion The data suggests that the use of a polypropylene knitted non-absorbable mesh for proximal humerus reconstruction may reduce dislocations and facilitate soft tissue attachment after tumor resection.     

Surface replacement of the humeral head in the rheumatoid shoulder

The clinical results obtained an average of 4.2 years after resurfacing of the humeral head in 72 rheumatoid shoulders showed 94% of the patients being pleased regarding pain relief and 82% reporting improved shoulder mobility. Shoulder function was significantly improved. The radiographs were analyzed regarding the position of the humeral head resurfacing cup, proximal migration of the humerus, and glenoid attrition during the follow-up period. Change of the distance between the superior margin of the cup and the greater tuberosity and/or change of inclination of the prosthesis were regarded as signs of prosthetic loosening. With that definition, 25% of the cups were found to be loose at follow-up. Prosthetic loosening, however, had no bearing on the clinical result. Also, no relationship was found between the position of the cup and the clinical outcome. Neither progressive proximal migration of the humerus in 38% of the shoulders nor central attrition of the glenoid in 22% of the shoulders showed any relationship to gain of mobility, pain relief, or functional ability.     

Proximal humeral resection and reconstruction

Resection of the proximal humerus may be required for control of benign, primary malignant, or metastatic neoplasms. The defect created by such a resection may spare the shoulder cuff muscles and deltoid (Malawer type IA) or remove them (Malawer type IB). Reconstruction of these defects and restoration of some degree of shoulder function may be accomplished by a variety of techniques. A technique of reconstruction with a composite allograft and endoprosthesis for type IA resections and the use of a proximal humeral prosthesis for type IB resections are described, and alternative methods are discussed.