Joint-preserving operations for elderly patients with advanced and late-stage coxarthritis

Forty-one hips in 38 elderly patients with osteoarthritis of the hips, operated on with joint preserving techniques at the age of 55 years or more, were analyzed clinically radiologically. Bilateral involvement was seen in 13 cases. Ten hips were operated on after this study, before the patients were 55 years old, or no operation has yet been done. The average age at operation was 59 years, and the average preoperative hip scores (Merle d'Aubigné) were as follows: pain 2.8; range of motion (ROM) 4.4; gait 3.4. Average preoperative hip flexion and abduction were 88° and 20° respectively. Mean follow-up period was 57 months, and mean final hip scores were: pain 5.1; ROM 4.6; gait 4.0. Significant improvement was seen in pain and gait scores but no improvement in ROM scores. Excellent and good scores were achieved in half of the cases. Failure was seen in four cases. Hip pain recurred in nine patients. Five out of these patients were classified as atrophic according to Bombelli's classification of osteoblastic response of osteoarthritis of the hip. The responsiveness of the femoral head influenced the clinical results of the joint-preserving operations.     

Total hip arthroplasty using the S-ROM modular stem after joint-preserving procedures for osteonecrosis of the femoral head

The aim of this study was to test the hypothesis that a previous joint-preserving procedure for osteonecrosis of the femoral head (ONFH) would compromise the outcome of a subsequent total hip arthroplasty. The clinical and radiographic results of total hip arthroplasty using the S-ROM stem (DePuy/Johnson & Johnson, Leeds, UK) in 36 hips with failed joint-preserving procedures for ONFH were compared with those in a matched control group of 39 osteonecrotic hips without a previous joint-preserving procedure. After a mean follow-up of 4.6 years, with the exception of 1 reoperation for polyethylene wear and osteolysis, no revisions due to mechanical failure of the prostheses had been performed in the study cohort of 36 hips. However, the study group had a longer operative time, more perioperative blood loss, a higher rate of intraoperative complications, and poorer postoperative ranges of hip motion than those in the control group. These results confirm the hypothesis that a previous joint-preserving procedure for ONFH poses technical challenges for a subsequent total hip reconstruction and might have a detrimental effect on the short-term clinical outcome.     

Relief from pain after Bombelli's valgus-extension osteotomy, and effectiveness of the combined shelf operation

Between 1979 and 1993, we treated 67 hips in 58 patients with severe osteoarthritis caused by congenital dislocation of the hip, employing Bombelli's valgus-extension osteotomy. The mean age of the patients was 43.6 years (range, 23–59 years). The mean follow-up period was 9.7 years (range, 5–16 years). Thirty-three of the 67 joints were followed-up for more than 10 years after the operation. Of the 67 joints, 31 were operated on by Bombelli's valgus-extension osteotomy combined with a shelf operation (combined group), and 36 by Bombelli's valgus-extension osteotomy alone (single group). Clinical evaluation was made according to the Japanese Orthopaedic Association (JOA) hip score system (JOA hip score). In order to assess the effectiveness of this operation in regard to sustained relief from pain after the operation, Kaplan-Meier survivor analysis was performed on the basis of pain score on the JOA hip score. The end-point of the Kaplan-Meier analysis was defined as a score of less than 20 points on the pain score at the time of follow-up or conversion to total hip arthroplasty. In order to analyze the factors that exacerbated pain and to assess the effectiveness of the combined shelf operation, the degree of superior displacement of the femoral head (measured from roentgenograms) after the operation was examined in relation to the pain score. The mean JOA hip score improved, from 56.1 ± 11.0 before the operation to 77.0 ± 16.1 at the latest follow-up. Kaplan-Meier analysis showed a survival rate of 79.4% 10 years after the operation. Superior displacement of the femoral head had gradually progressed with time after the operation in patients with and without the combined shelf operation. Displacement of the femoral head was positively correlated with the acetabular angle of the weight-bearing surface (WBS angle) (sourcil) preoperation. The mean pain score in the combined group was significantly higher than that in the single group 6 to 9 years after the operation. The results of our assessments led us to conclude that Bombelli's valgus-extention osteotomy is satisfactory as far as clinical and radiological evaluations are concerned, as relief from the pain has continued for more than 10 years after the operation. The combined shelf operation is effective for relieving pain in severe osteoarthritis caused by congenital dislocation of the hip. Received for publication on Nov. 4, 1998; accepted on Aug. 11, 1999     

Glenoid wear after shoulder hemiarthroplasty: quantitative radiographic analysis

Symptomatic glenoid arthrosis may limit the long-term success of shoulder hemiarthroplasty in patients who are young and functionally demanding. The principal objective of the current study was to quantify glenoid wear after proximal humeral replacement in young, active subjects. Eight patients, ages 21 to 60 years (mean, 45 years), met inclusion criteria. The mean followup was 43 months. Functional scores for the cohort averaged 60% of age and gender-adjusted healthy subjects (range, 28%-84%). Glenohumeral joint space was measured on serial axillary radiographs using a Microscribe 3-DX digitizing device (measurement accuracy, 0.23 mm). Progressive glenoid wear was found in all eight patients. The mean decrease was 2 mm (range, 1.3-2.8 mm), a 68% decrease in glenohumeral joint space. Glenoid cartilage wear also was correlated with Constant and Murley scores. Patients with residual joint spaces less than 1 mm had a mean score of 50%, compared with a score of 71% for patients with joint spaces greater than 1 mm. There were no correlations between wear and mechanism of injury, duration of symptoms, and prior surgery. This study suggests that glenoid cartilage erosion can be expected routinely after humeral head replacement in young, active individuals, and that such wear may adversely affect function or necessitate conversion to total shoulder arthroplasty.     

Correlation between radiographic severity of knee osteoarthritis and future disease progression. Results from a 3-year prospective,placebo-controlled study evaluating the effect of glucosamine sulfate

OBJECTIVE: To investigate the relationship between baseline radiographic severity of knee osteoarthritis (OA) and the importance of long-term joint space narrowing. DESIGN: Sub-analysis from a three-year randomized, placebo-controlled, prospective study, of 212 patients with knee OA, recruited in an osteoarthritic outpatient clinic and having been part of a study evaluating the effect of glucosamine sulfate on symptom and structure modification in knee OA. MATERIAL AND METHODS: Measurements of mean joint space width (JSW), assessed by a computer-assisted method, were performed at baseline and after 3 years, on weightbearing anteroposterior knee radiographs. RESULTS: In the placebo group, baseline JSW was significantly and negatively correlated with the joint space narrowing observed after 3 years (r=-0.34, P=0.003). In the lowest quartile of baseline mean JSW (<4.5mm), the JSW increased after 3 years by (mean (S.D.)) 3.8% (23.8) in the placebo group and 6.2% (17.5) in the glucosamine sulfate group. The difference between the two groups in these patients with the most severe OA at baseline was not statistically significant (P=0.70). In the highest quartile of baseline mean JSW (>6.2mm), a joint space narrowing of 14.9% (17.9) occurred in the placebo group after 3 years while patients from the glucosamine sulfate group only experienced a narrowing of 6.0% (15.1). Patients with the most severe OA at baseline had a RR of 0.42 (0.17-1.01) to experience a 0.5mm joint space narrowing over 3 years, compared to those with the less affected joint. In patients with mild OA, i.e. in the highest quartile of baseline mean JSW, glucosamine sulfate use was associated with a trend (P=0.10) towards a significant reduction in joint space narrowing. CONCLUSION: These results suggest that patients with the less severe radiographic knee OA will experience, over 3 years, the most dramatic disease progression in terms of joint space narrowing. Such patients may be particularly responsive to structure-modifying drugs.     

Does the joint line matter in revision total knee replacement?

We identified 148 patients who had undergone a revision total knee replacement using a single implant system between 1990 and 2000. Of these 18 patients had died, six had developed a peri-prosthetic fracture and ten had incomplete records or radiographs. This left 114 with prospectively-collected radiographs and Bristol knee scores available for study. The height of the joint line before and after revision total knee replacement was measured and classified as either restored to within 5 mm of the pre-operative height or elevated if it was positioned more than 5 mm above the pre-operative height. The joint line was elevated in 41 knees (36%) and restored in 73 (64%). Revision surgery significantly improved the mean Bristol knee score from 41.1 (SD 15.9) pre-operatively to 80.5 (SD 15) post-operatively (p < 0.001). At one year post-operatively both the total Bristol knee score and its functional component were significantly better in the restored group than in the elevated group (p < 0.01). Overall, revision from a unicondylar knee replacement required less use of bone graft, fewer component augments, restored the joint line more often and gave a significantly better total Bristol knee score (p < 0.02) and functional score (p < 0.01) than revision from total knee replacement. Our findings show that restoration of the joint line at revision total knee replacement gives a significantly better result than leaving it unrestored by more than 5 mm. We recommend the greater use of distal femoral augments to help to achieve this goal.     

Phalangeal osteotomy versus first metatarsal decompression osteotomy for the surgical treatment of hallux rigidus: a prospective study of age-matched and condition-matched patients.

The surgical options for hallux rigidus in the presence of painful but moderate degenerative metatarsophalangeal joint disease are limited to either joint-destructive or joint-preserving procedures. The following study compared the effectiveness of 2 joint-preservation procedures. Forty-nine patients, with a mean age of 53 years, underwent phalangeal osteotomy and were reviewed at an average 29 months postoperatively. A subsequent group of 59 patients, with a mean age of 51 years, underwent first metatarsal decompression osteotomy and were reviewed at an average 15 months postoperatively. In the phalangeal osteotomy group, 65% of patients were completely satisfied, 24% were satisfied with reservation, and 11% were dissatisfied. Three patients suffered continued metatarsophalangeal joint pain, 3 developed hallux interphalangeal joint pain, and 4 patients developed transfer metatarsalgia. The postoperative decrease from 36 degrees to 35 degrees in mean peak hallux dorsiflexion on walking was not significant. In the first metatarsal decompression osteotomy group, 54% were completely satisfied, 13.5% were satisfied with reservations, and 32% were dissatisfied. Continued metatarsophalangeal joint pain occurred in 2 patients, 18 developed transfer metatarsalgia, and 6 of these patients required lesser metatarsal osteotomy. Peak hallux dorsiflexion during walking increased from 36 degrees to 42 degrees (P < .001). First metatarsal decompression osteotomy will increase joint range of motion but the risk of complication and patient dissatisfaction is less after phalangeal osteotomy. Neither procedure could be considered definitive for hallux rigidus.     

The Effect of Joint Line Elevation on Patient-Reported Outcomes After Contemporary Revision Total Knee Arthroplasty

BackgroundJoint line elevation in revision total knee arthroplasty (rTKA) is considered a risk factor for inferior outcomes, engendering a dogmatic protocol of joint line restoration. However, this precedent is based on historical data using rudimentary revision systems and unvalidated outcome measures. This study’s purpose was to evaluate the effect of joint line height elevation on validated patient-reported outcome measures (PROMs) using modern revision implants.MethodsA total of 327 rTKAs performed at a single institution were reviewed. Surgical technique prioritized flexion-extension gap balancing and accepted joint line elevation if necessary to achieve a balanced flexion space. Radiographic measurements included changes in joint line height (from preoperative and calculated “intended” anatomic/native) and change in posterior condylar offset. Prospectively collected PROMs were evaluated using multivariate regression.ResultsThe mean joint line elevation from preoperative and “intended” to postoperative joint line was 4.9 ± 5.7 mm and 7.2 ± 6.6 mm, respectively. The mean increase in posterior condylar offset was 1.0 ± 4.6 mm. Patients within ±5 mm of preoperative joint line height were 3.88× more likely to achieve the substantial clinical benefit for Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (P = .004). An increase from intended joint line height >5 mm was not associated with differences in any other PROMs (P ≥ .165).ConclusionsIn contemporary rTKA, recreating the joint line within 5 mm of preoperative improves knee-specific health outcomes. These data support approximating native joint line height as a viable technique to optimize flexion gap balance and subsequent patient outcomes in rTKA.Level of EvidenceLevel III retrospective cohort study.     

Quantification of the Radiographic Joint Space Width of the Ankle

Quantification of joint space width of the ankle could provide information essential to evaluate the effects of potential disease-modifying agents and adverse effects of devices intended to ameliorate osteoarthritis elsewhere in the lower extremity. Current methods require proprietary software or have not been well validated; our purpose was to develop and assess the reliability of a digital joint space width quantification method using public access software. We studied 95 patients, asymptomatic in the ankles and without history of ankle trauma, but with symptomatic medial knee osteoarthritis, participating in an ongoing longitudinal trial. Weightbearing anteroposterior radiographs of the ankle and supine radiographs of the pelvis were assessed, and the narrowest medial and lateral tibiotalar joint space widths and hip joint space widths were measured using Image J software (US NIH, Bethesda, MD). Medial joint space widths were 2.56 ± 0.50 and 2.55 ± 0.48 mm, and lateral joint space widths were 2.45 ± 0.55 and 2.44 ± 0.52 mm, for right and left ankle, respectively. Coefficients of variation for repeat measurements by the same observer were 1.13% and 4.5%, and by different observers 7.30% and 7.27%, for medial and lateral joint space widths, respectively. Men had wider joint space widths than women when accounting for height. Joint space width of the ankle correlated with the joint space width of the hip and with height and weight, but not with age. One or more of the authors have received funding from the National Institutes of Health, Bethesda, MD (NIH 1P50 AR048941) (JAB) and the Turkish Society for Education and Research in Rheumatology (RAED-Romatoloji Arastırma ve Egitim Dernegi) (BG). Each author certifies that his or her institution has approved the human protocol for this investigation, that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained. This work was performed at Gazi University and at Rush Medical College.     

骶髂螺钉置入S1椎弓根的形态学研究

目的研究S1椎弓根的形态学特点，探讨经骶髂关节置入S1椎弓根螺钉的可行性。方法测量16具尸体骨盆标本双侧S1椎弓根前后缘的高度、深度(S1椎弓根最狭窄处的宽度)、骶翼深度、骶翼高度。测量骨盆出口位X线片上S1椎弓根的高度，并与肉眼解剖比较。在轴位CT图像上测量髂骨后缘到骶翼、S1椎弓根、S1椎弓根纵轴的距离、髂骨外板与骶椎前缘皮质的距离。观察S1椎弓根矢状切面，评估置入2枚经S1椎弓根骶髂螺钉的安全区。结果椎弓根前后缘的高度平均为30．2mm、26．Imm，椎弓根深度和骶翼深度平均为27．8mm、45．8mm，骶翼后部平均高度为28．7mm。骨盆出口位X线片上S1椎弓根的平均高度是20mm，小于肉眼解剖测量结果(P＜0．0001)。轴位CT图像上，S1椎弓根纵轴在髂骨外板投影点到髂骨后缘的距离平均为32．5mm，到坐骨大切迹最高点的距离平均为38．6mm，髂骨外板到S1椎体前缘皮质的距离平均为105．2mm。结论置入1枚S1椎弓根螺钉是安全的，常规置入2枚椎弓根螺钉可能较困难。     

四级分析法评估成人颈椎关节突退变

目的探讨一种新的成人下颈椎关节突关节退变的评级方法,为临床观测提供量化的评级标准。方法选用20例在读学生为正常组和40例颈椎病患者为病理组,分别行螺旋CT扫描并重建,测量下颈椎关节突关节横断面长度、宽度及关节间隙大小,计算出正常值范围;制定下颈椎关节突关节退变的评级标准。数据用SPSS 13.0统计软件包进行统计学分析,计算正常组、病理组各数据的均数及标准差;同一关节突关节左右数据间比较行配对t检验,正常组和病理组同一节段的各数据比较用独立样本t检验。结果 （1）正常组下颈椎关节突关节各测量数据左右差异均无统计学意义,取双侧均值。C3-4、C4-5、C5-6、C6-7关节突关节横断面长度分别为：（10.84±0.94）mm、（11.57±0.85）mm、（11.83±0.96）mm、（12.57±0.88）mm;关节突关节横断面宽度分别为：（10.44±0.99）mm、（10.56±0.91）mm、（10.50±1.06）mm、（9.49±0.68）mm;关节间隙中部（J2）最大,分别为：（1.49±0.12）mm、（1.44±0.10）mm、（1.43±0.09）mm、（1.45±0.11）mm;关节间隙两侧（J1、J3）略窄且基本对称。（2）病理组下颈椎关节突关节各测量数据左右差异均无统计学意义,取双侧均值。C3-4、C4-5、C5-6、C6-7关节突关节横断面长度分别为：（10.83±0.83）mm、（11.44±0.85）mm、（12.26±0.70）mm、（12.67±0.74）mm;关节突关节横断面宽度分别为：（10.55±0.98）mm、（10.98±1.06）mm、（10.96±0.85）mm、（9.75±0.81）mm;关节间隙中部（J2病）最大,分别为：（1.34±0.17）mm、（1.30±0.27）mm、（1.34±0.17）mm、（1.25±0.12）mm;关节间隙两侧（J1病、J3病）略窄且基本对称。（3）正常组和病理组间比较：C5-6关节面长度间差别有统计学意义;C4-5、C5-6关节面宽度间差别有统计学意义;C3-4、C4-5、C5-6、C6-7关节间隙大小间差别均有统计学意义;病理组关节突关节退变的特征表现为：关节突肥大、骨赘形成、关节面不规则、关节间隙狭窄、软骨下骨坏死、软骨下骨囊性变。结论自行设计的一种新的下颈椎关节突关节退变的评级标准,分为0-Ⅲ级,该评级标准是一个简单实用的影像学评估方法。     

Osteoblastic response to osteoarthrosis of the hip does not predict outcome of cementless cup fixation: 79 patients followed for 5-11 years

We evaluated the influence of osteoblastic response to osteoarthrosis of the hip on the outcome of cementless acetabular cup after 91 total hip replacements in 79 patients. Of the 91 hips, 23 were atrophic, 37 normotrophic, and 31 hypertrophic, according to Bombelli's criteria. There were no clinical or radiographic differences among the three groups at the final follow-up (average 7 (5-11) years), when stable bone growth had been achieved by all of the acetabular cups in patients with the atrophic type, 35/37 of the normotrophic type, and all the hypertrophic type. Revision of the acetabular cup was performed on 1 hip of the normotrophic type, in connection with severe polyethylene liner wear and progressive osteolysis.     

Osteoblastic response to osteoarthrosis of the hip does not predict outcome of cementless cup fixation: 79 patients followed for 5-11 years

We evaluated the influence of osteoblastic response to osteoarthrosis of the hip on the outcome of cementless acetabular cup after 91 total hip replacements in 79 patients. Of the 91 hips, 23 were atrophic, 37 normotrophic, and 31 hypertrophic, according to Bombelli's criteria. There were no clinical or radiographic differences among the three groups at the final follow-up (average 7 (5-11) years), when stable bone growth had been achieved by all of the acetabular cups in patients with the atrophic type, 35/37 of the normotrophic type, and all the hypertrophic type. Revision of the acetabular cup was performed on 1 hip of the normotrophic type, in connection with severe polyethylene liner wear and progressive osteolysis.     

两种后路椎间植骨方法治疗腰椎滑脱的疗效比较研究

目的探讨后路椎间融合(pasterior lumber interbody fusion,PLIF)应用Cage及椎弓根钉技术后,有无必要加用椎间自体植骨治疗腰椎滑脱. 方法 2003年3月～2004年3月,对27例腰椎滑脱症患者行后路椎间植骨融合术.采用Cage及椎弓根钉技术治疗15例(A组),其中男4例,女11例;年龄53～68岁.病变部位位于L4节段9例,L5节段6例;术前平均椎间隙高度为5.4±2.3 mm,平均滑脱率为36.8%±7.2%.采用Cage及椎弓根钉技术加用椎间自体植骨治疗12例(B组),其中男3例,女9例;年龄53～65岁.病变部位位于L4节段8例, L5节段4例;术前平均椎间隙高度为5.7±2.5 mm,平均滑脱率为37.8%±6.2%.对两组患者进行失血量、住院日、疼痛度和缓解程度、融合率及并发症,以及术后椎间隙高度、滑脱率及融合率进行分析比较. 结果术后患者均获随访24～38个月,A组随访时间24～36个月,B组随访时间24～38个月.两组患者随访时间,性别,病变部位,术前椎间隙高度,平均滑脱率,失血量,住院日,融合时间均无统计学差异(P>0.05);但疼痛度及缓解程度、融合率,B组均好于A组,差异有统计学意义(P<0.05).A组最后随访平均椎间隙高度5.8±2.2 mm,平均滑脱率为25.6%±7.2%,B组为6.2±2.5 mm和24.1%±7.4%,两组比较差异有统计学意义(P<0.05). 结论 PLIE手术应用Cage及椎弓根钉技术加用椎间自体植骨,有助于恢复和保持腰骶椎生理曲度,防止后期的椎间隙高度丢失及滑脱率的增加,可能利于手术后长期疗效的保持.     

In vivo serial joint space measurements during dynamic loading in a canine model of osteoarthritis

OBJECTIVE: To devise a reliable, sensitive method to measure joint space in vivo during dynamic loading. Additionally, to determine if dynamic joint space changes were related to the severity of long-term cartilage damage. DESIGN: Subjects were 23 adult foxhounds (18 experimental, 5 control). Experimental subjects had surgically transected cranial cruciate ligaments (CCL). Dynamic joint space was serially measured in vivo over 2 years using a unique high speed stereo radiographic system in combination with subject-specific computed tomography reconstructions. RESULTS: Dynamic joint space was measured in vivo with a within-day precision of 0.09 mm. Half of the experimental subjects developed minor articular cartilage damage and the other half developed severe articular cartilage damage in the medial knee compartment. Joint space during treadmill running increased significantly in the minor damage group in both the medial (+0.61 mm, P = 0.036) and lateral (+0.84 mm, P = 0.002) compartments of the knee. Dynamic joint space in the severe damage group did not increase significantly on either the medial (+0.27 mm, P = 0.408) or lateral (+0.44 mm, P = 0.199) side. The majority of the change in joint space occurred the first year after CCL transection. Medial meniscus damage was related to severity of medial articular cartilage damage (tau = 0.447, P = 0.003). The minor damage group developed 73% of all osteophytes noted at dissection. CONCLUSIONS: This technique is a precise tool for measuring joint space serially in vivo under dynamic loading conditions. The data suggest decreased severity in long-term articular cartilage damage is related to: osteophyte formation, less severe medial meniscus damage and increased joint space the first 12 months after injury.     

Reconstruction of the severely atrophic mandible using calvarial split bone grafts for implant-supported oral rehabilitation.

OBJECTIVES: This article describes reconstruction of the severely atrophic mandible using calvarial bone grafts for implant-supported prosthetic oral rehabilitation. The study aim was to evaluate the efficacy of the treatment by determining implant survival and complication rates, and the extent of the postoperative graft resorption. STUDY DESIGN: Ten patients who underwent the treatment were followed clinically and radiologically using panoramic radiographs and CT scans during a mean postoperative period of 30 months. RESULTS: Good bone healing was observable 6 months postoperatively. The height reduction measured on panoramic radiographs was insignificant (mean 0.68 mm). Only minor complications occurred. Implant survival was 95%. Prosthodontic treatment was successfully performed in all cases, resulting in an improvement of oral function. Histological analysis of 1 bone biopsy showed minimal resorptive changes in otherwise very dense bone. CONCLUSION: Augmentation using calvarial grafts is a promising treatment alternative for the severely atrophic mandible.     

Anatomic Description of the Fourth and Fifth Tarsometatarsal Articulation: A Cadaveric Study

The fourth and fifth tarsometatarsal joint, consisting of the fourth and fifth metatarsal and the cuboid, imparts a significant amount of motion to the foot during ambulation. Injury to this joint complex, through chronic deformation or acute trauma, often necessitates arthroplasty, arthrodesis, or fusion. Currently, there exists no studies that investigate the anatomy of this articulation. The purpose of this study is to describe the medial and lateral anterior cuboid articulations which allows for surgical planning and the advancement of hardware design. Twenty fresh-frozen below-the-knee cadaver legs were thawed and the cuboids were excised. The width and height of the entire joint complex were measured as the longest span across the total articular surface of the anterior cuboid. The width and height of each articular facet were recorded as the span across the geometric bisection of each individual surface. The mean anterior cuboid articulation width and height was 25.62 mm and 16.74 mm, respectively. The mean medial cuboid articulation width and height was 11.7mm and 13.65 mm, respectively. The mean lateral cuboid width and height was 16.74 mm and 12.78 mm, respectively. The medial articulation maintained a larger mean height and narrower mean width than the lateral facet (p < .05). The unique anatomy of the lateral tarsometatarsal joint complex plays an important functional role and requires attention when deciding between arthrodesis or arthroplasty. Increasing the understanding of the clinical anatomy of this joint will better prepare surgeons and product designers to anticipate hardware needs.     

Meniscus tears accelerate joint space loss and lateral meniscal extrusion increases risk of knee arthroplasty in middle-aged adults

We sought to use publicly available data from the Osteoarthritis Initiative (OAI), a multicenter prospective cohort study, to determine the rate of joint space loss and likelihood of knee arthroplasty due to magnetic resonance imaging (MRI)-diagnosed meniscal tears or meniscal extrusion in middle-aged adults with no to mild knee osteoarthritis. Participants (n = 2199; mean age, 60.2 years) with Kellgren-Lawrence osteoarthritis grades 2 (mild) (48.7%) or 0 to 1 (none) (51.3%) underwent knee MRIs at enrollment and were followed radiographically for 8 years and for total knee arthroplasty (TKA) for 9 years. Rate of joint space loss and risk of arthroplasty due to meniscal tears and/or extrusion were determined by multivariate modeling. Prevalence of baseline medial meniscus tears was 21.3% and lateral tears was 12.8%; 26.9% had medial meniscal extrusion (79.6%, <2 mm; 20.4%, +2 mm) and 5.4% had lateral extrusion (75.9%, <2 mm; 24.1%, +2 mm). Median medial joint space loss was 0.06 mm/y and lateral was 0.05 mm/y. Medial tears regardless of extrusion were associated with accelerated medial joint space loss (additional mean, 0.05 mm/y; P = .001). Lateral tears were associated with accelerated lateral joint space loss (additional 0.09 mm/y; P < .001) as was lateral extrusion (additional 0.10 mm/y; P < .001). The yearly incidence of knee arthroplasty was 0.5% without lateral extrusion, 1.5% with extrusion less than 2.0 mm, and 3.7% with extrusion greater than or equal to 2.0 mm. Both medial and lateral tears accelerate joint space loss in middle-aged adults. Lateral meniscal extrusion further accelerates joint space loss and increases risk of progression to TKA within 9 years.