股骨假体旋转对线技术对髌骨轨迹优化的临床研究

目的进行人工全膝关节置换术中股骨假体旋转对线技术对髌骨轨迹作用的随机化、前瞻性的临床研究。方法150例骨关节炎患者接受初次人工全膝关节置换术,其中40例接受双膝同期置换,密封信封抽样随机分组确定股骨假体旋转对线的参照标准,以"布巾钳试验"评价髌骨轨迹,决定是否作外侧支持带松解。结果股骨上髁轴组10个膝需行外侧支持带松解,股骨后髁轴组23个膝需行外侧支持带松解,两组差异有显著性(P<0·05)。结论股骨假体旋转对线对于髌骨轨迹的优劣有着显著影响,股骨上髁轴作为旋转对线的参照轴可以明显改善髌骨轨迹。     

Prospective comparative study of intraoperative “Towel clip test” and “Vertical patella test” assessing lateral retinaculum tightness in patients undergoing TKA

BackgroundProper patellar tracking is one of the most important aspect of TKA to ensure good functional outcome. A patellar tracking problem noted intraoperatively serves as a warning sign and should prompt the surgeon to reassess position of each component. Various tests are there to assess lateral retinaculum tightness viz. "No thumb test", "Towel clip test". A new test "Vertical patella test" is described to assess lateral retinaculum tightness. A study was conducted to assess the effectiveness, correlation and validity of two techniques.Materials & MethodsPatients >50 years of age and with diagnosis of Osteoarthritis knee having less than 30 varus and flexion deformity going in for primary TKA were selected with a sample size of 100 knees in a tertiary care centre. Revision cases or patients with flexion contracture more than 30, complex knee surgery; with pre existing patellar tilt were excluded from study.ResultsResults of both tests were found to correlate in 75% of case with sensitivity of 96.65% and specificity of 75.00%. Kappa came out to be 0.634 which shows good agreement of vertical patella test and towel clip test. Result was computed using excel and SPSS and was found to be significant with p value< 0.05. Lateral retinaculum release was done in 8 knees.ConclusionsVertical patella test correlates with towel clip test, is easy to perform and saves time. The limitation of our study was small sample size.     

关节镜下外侧支持带松解治疗髌骨外侧高压综合征

目的探讨关节镜下外侧支持带松解治疗髌骨外侧高压综合征的效果和临床意义.方法采用关节镜下外侧支持带松解术治疗39例(51膝)髌骨外侧高压综合征.男1例(1膝),女38例(50膝);单膝27例,双膝12例;平均年龄49.6岁(28～71岁).临床症状以髌股关节钝痛为特点,疼痛位置不易确定,髌股关节负荷过度的活动会使疼痛加重.物理检查见Q角增大(＞20°)45膝,髌软骨外侧小面抠触痛50膝,外侧支持带压痛39膝,被动髌骨倾斜试验阳性51膝,内外侧滑动试验阳性49膝,压髌试验阳性51膝.X线检查轴位片见髌股对合角异常32膝.术中在关节镜监视下,用射频汽化钩刀松解外侧支持带,必要时可向近端扩大松解范围,切断部分股外侧肌,达到完全松解.结果术后所有病例均得到随访,平均随访14.5个月(3～26个月).疗效评定参照改良Lysholm评分标准,优37膝,良12膝,可2膝.Lysholm评分从术前平均(62.04±5.98)分(49～75分)提高到术后平均(93.71±3.55)分(86～100分),有显著性差异(t=6.63,P＜0.001).髌股对合角异常的32膝中术后有30膝髌股对合角恢复正常(94%).术后5膝有血肿形成(10%).结论关节镜下外侧支持带松解是一种微创的软组织平衡手术,能够有效地缓解髌骨外侧高压综合征引起的髌股关节疼痛,且并发症较少.     

Evaluation of patellar retinacular tension during total knee arthroplasty: Special emphasis on lateral retinacular release

Tension of a suture placed to the patella to close the medial capsule during 35 primary total knee arthroplasties was measured. The increase in tension with flexion after arthrotomy was significantly smaller in 10 knees with a subvastus incision (subvastus group) than in 25 knees with a standard medial parapatellar incision (standard group). With the prosthesis in place, the patella showed maltracking with the no-thumb technique in 1 knee (10%) of the subvastus group and in 9 knees (36%) of the standard group. A lateral retinacular release was performed in 5 of these 10 knees but not in the remaining 5 knees because the increase in tension was a minimum. There was no case of patellar maltracking at an average follow-up period of 2.1 years after surgery, suggesting that a lateral release is not always needed if retinacular tension shows no significant increase, even cases where the patella dislocates with the no-thumb technique.     

Long-term functional outcome after lateral patellar retinacular release in adolescents: an observational cohort study with minimum 5-year follow-up

BACKGROUND: Lateral patellar retinacular release has been recommended for patients with patellar tilt, tight lateral retinaculum, patellar subluxation, patellar dislocation, and patellofemoral pain. Studies of long-term outcomes after lateral release are limited, especially for differing indications. HYPOTHESIS: Adolescents do well after lateral retinacular release in the 5- to 22-year time frame. METHODS: Patients having undergone lateral retinacular release between the years of 1981 and 1999 were contacted. Evaluation was by the Cincinnati and Lysholm scales and by level of satisfaction and need for reoperation. RESULTS: One hundred forty knees were studied. Mean age at operation was 15.4 years (SD, 2.7 years). Average follow-up was 8.5 (SD, 4.1 years; range, 5.2-22.5 years). Twenty-five patients had needed reoperation, indicating failure of the index operation. Kaplan-Meier survivorship was 78% at 15 years. Cincinnati and Lysholm scores indicated well-functioning knees in those not requiring reoperation. Overall satisfaction improved as time from operation increased.Comparisons were made between the group requiring reoperation and those who did not. Focus was placed on knees with patellar maltracking or tilt versus patellar instability and between males and females. No differences were found among groups for reoperation rate, level of satisfaction, average Lysholm score, or average Cincinnati score. There were no differences in demographics or outcome measures between patients with patellar instability and those with tilt. Instability patients trended toward higher reoperation rates than did tilt patients, but the difference was not significant. There were no differences between males and females. CONCLUSION: The majority of patients are satisfied with their knee 5 to 22 years after lateral patellar retinacular release and scored well on questions rating knee health and function.     

A clinical comparison of patellar tracking using the transepicondylar axis and the posterior condylar axis

Two different methods for femoral component rotation in total knee arthroplasty (TKA) were compared with regard to the need for lateral retinacular release and 3-year follow-up knee society scores of both patellofemoral function and 3-year radiographs of the patella. The posterior condylar axis was used in 1322 consecutive primary TKAs, and the transepicondylar axis (TEA) was used in 1059 consecutive primary TKA. A significant decrease in lateral retinacular release was observed from 56.9% (752 knees) using the posterior condylar axis down to 12.3% (130 knees) using the TEA. No significant differences in knee society scores were observed between the 2 groups with regard to stair climbing, pain, patella radiographs, or range of motion. Routine use of the TEA is recommended for determining femoral component rotation in TKA.     

止血带对全膝关节置换术中股骨远端旋转定位时髌骨轨迹的影响

目的 探讨止血带对全膝关节置换术中以外科髁上轴线为股骨远端旋转定位线的髌骨轨迹的影响.方法 2002年12月至2008年8月,首选以外科髁上轴线为股骨远端旋转定位标志的初次全膝关节置换349例(526膝),男124例(155膝),女225例(371膝);年龄33～84岁,平均68岁.膝内翻387膝,膝外翻94膝.均使用同一种保留后十字韧带的活动平台假体,由同一位手术医生操作.采用前内侧髌旁入路,以外科髁上轴线为股骨远端旋转定位线,以no thumb test检测髌骨轨迹.对髌骨轨迹不良者,缝合髌骨内上缘支持带并松开止血带.对再次检查髌骨轨迹不良者行外侧支持带松解术.术后3个月患者能够极度屈曲膝关节时摄X线片检查髌骨轨迹.结果 术中no thumb test阳性138膝,其中半脱位12膝(膝外翻),髌骨倾斜126膝(膝外翻74膝).缝合髌骨内上缘支持带并松开止血带后,no thumb test阳性40膝,其中半脱位8膝(膝外翻),髌骨倾斜32膝(膝外翻29膝).髌骨外侧支持带松解率7.6%(40/526),膝外翻松解率39.4%(37/94).结论 在全膝关节置换术中,高压止血带对髌骨轨迹有干扰作用.术中缝合髌骨内上缘支持带并松开止血带,可降低外侧支持带松解率.     

The native femoral sulcus as the guide for the medial/lateral position of the femoral component in knee arthroplasty: Normal patellar tracking in 690/700 knees—a prospective evaluation

Background?There are no simple guidelines for the medial/lateral positioning of the femoral component in knee arthroplasty (TKA). I therefore conducted a prospective study to evaluate the use of the native femoral sulcus as a guide for the medial/lateral positioning.

Patients and methods?Between 1997 and 2001, 700 primary TKAs (Nexgen Zimmer, cruciate retaining prostheses) were performed in 508 patients with the femoral component positioned according to the native femoral sulcus. Intraoperatively, no thumb technique was used to check the patellar tracking. The median follow-up period was 4.5 (4.0–5.5) years.

Results?Intraoperatively, lateral retinacular release was performed in 3 knees. In the postoperative radiographic evaluation of patellar tracking, 10 knees (1.4%) had lateral tilting of the patella. The postoperative HSS scores were 93 (85–98).

Interpretation?The native femoral sulcus may be used as an effective and simple guide for the medial/lat-eral femoral component position.     

Effect of rotational alignment on patellar tracking in total knee arthroplasty

Forty-four consecutive patients (65 knees) who underwent identical condylar type total knee arthroplasty were evaluated retrospectively. In 22 of the patients (32 knees), the femoral component was set parallel to the posterior condylar axis (neutrally aligned group). In the remaining 22 patients (33 knees), it was set in an external rotation position of 3 degrees to 5 degrees relative to the axis (externally aligned group). Of the total knee arthroplasties in the neutrally aligned group, 34% required lateral release, compared with only 6% in the externally aligned group; patellar tracking in the externally aligned group was significantly better than that in the neutrally aligned group. Postoperative measurements performed using computed tomography scans showed that the mean angle between the prosthetic posterior condylar axis and the transepicondylar axis was 7.9 degrees in the neutrally aligned group and 3.2 degrees in the externally aligned group. The external rotation setting of the femoral component diminished the need for lateral retinacular release and may decrease the rate of patellofemoral complications that occur after total knee arthroplasty.     

Results of a second-generation constrained condylar prosthesis in primary total knee arthroplasty

This is a prospective study of the results of a second-generation modular constrained condylar knee (CCK) prosthesis in primary total knee arthroplasty. Of 418 consecutive total knee arthroplasties performed by 1 surgeon, a second-generation modular CCK prosthesis was indicated for intraoperative stability in 30 knees (7.2%). Three knees were lost to follow-up, and 27 knees had a mean follow-up time of 5.4 years (range, 2-11.5 years). All tibial components had a cemented 35-mm stem extension, and 26 femoral components had a 100-mm uncemented stem extension. The indication for use of the CCK components was most commonly severe valgus deformity and incompetent medial collateral ligament. There were no revisions for loosening, patella problems, or tibial post fracture. A lateral retinacular release of the patella was performed in 6 knees (22%). An asymptomatic, minimally displaced patella fracture was noted in 2 knees (7.4%). Constrained condylar knees are used infrequently now but are successful for the treatment of the unstable primary knee that cannot be balanced. These results may be design specific.     

Subvastus and medial parapatellar approaches in total knee arthroplasty

This retrospective study compared the outcome of two consecutive groups of patients having primary total knee arthroplasty. The arthroplasties were performed in the first group (169 arthroplasties in 143 patients) from 1988 to 1992 using a medial parapatellar approach, and in the second group (167 arthroplasties in 148 patients) from 1992 to 1996 using a subvastus approach. The patient outcomes were evaluated at 6 months, and were based on clinical and radiographic measures, occurrence of intraoperative lateral retinacular release, and incidence of postoperative patellar subluxation. There were no significant differences between the two groups for range of motion, Knee Society knee and function scores, and stair climbing ability. The patella tracked centrally in significantly more knees with the subvastus approach (139 of 167 knees, 83%) than with the parapatellar approach (107 of 169 knees, 63%). There were significantly fewer knees in the subvastus group requiring a lateral retinacular release (62 of 167 knees, 37%), compared with the parapatellar group (113 of 169 knees, 67%). The authors concluded that the subvastus approach led to improved patellar tracking and stability. Although the surgical and rehabilitative protocols were identical for both groups, the results may have been affected by changing circumstances during the 9-year period of the study.     

Preoperative computed tomography scanning and arthroscopy in predicting outcome after lateral retinacular release.

We initiated a study to look at preoperative, flexed-knee, midpatellar computed tomography (CT) scans and intraoperative arthroscopic findings of lateral patellar articular degeneration in predicting the results after lateral retinacular release for failed nonoperative treatment of anterior knee pain. Twenty patients with 30 painful knees underwent preoperative flexed-knee, midpatellar CT scans that were retrospectively classified by the method of Fulkerson into normal alignment, lateral subluxation, lateral patellar tilt, and combined tilt and subluxation. Arthroscopy was performed before open lateral release. The lateral facet of the patella was graded as either minimal changes (Outerbridge I or II) or advanced (Outerbridge III or IV) changes. Patients were followed for a minimum of 2 years and graded on a standard patellofemoral rating scale. Only 22 of 30 knees that were thought to be clinically malaligned, actually were malaligned by CT scan; eight CT scans were interpreted as normal. The results were further stratified into group A (CT-documented tilt, minimal facet changes), group B (CT-documented tilt, advanced facet changes), and group C (normal CT). Ninety-two percent of group A were rated good or excellent. Twenty-two percent of Group B rated good/excellent, 33% fair, 44% poor. Only 13% of group C rated good (one patient). Based on the results of the study, we recommend lateral release for anterior knee patients with CT-proven patellar tilt who have not responded to conservative treatment and have minimal facet changes with minimal or no subluxation. Lateral retinacular release should not be offered as a treatment to the patient with a normally aligned patella because poor results will most likely result.     

Treatment of chondromalacia patellae by lateral retinacular release of the patella

A series of 59 knees in 58 patients were surgically treated from 1977 to 1982 for chondromalacia patellae, and were followed for an average of 1.2 to 4.6 years after the operation. The operative procedure was open lateral retinacular release in all knees. In knees with recurrent patellar subluxation, the number of poor results increased from 24% to 70%, and in knees with no subluxation from 21% to 24%. The difference after 4.6 years was statistically significant. No correlation between the severity or location of the cartilage changes and the operative effect was found. Open lateral retinacular release is an acceptable treatment of chondromalacia patellae without subluxation of the patella, whereas in the presence of recurrent subluxation, the release does not correct the basic biomechanical disturbance.     

The native femoral sulcus as the guide for the medial/lateral position of the femoral component in knee arthroplasty: Normal patellar tracking in 690/700 knees--a prospective evaluation

BACKGROUND: There are no simple guidelines for the medial/lateral positioning of the femoral component in knee arthroplasty (TKA). I therefore conducted a prospective study to evaluate the use of the native femoral sulcus as a guide for the medial/lateral positioning. PATIENTS AND METHODS: Between 1997 and 2001, 700 primary TKAs (Nexgen Zimmer, cruciate retaining prostheses) were performed in 508 patients with the femoral component positioned according to the native femoral sulcus. Intraoperatively, no thumb technique was used to check the patellar tracking. The median follow-up period was 4.5 (4.0-5.5) years. RESULTS: Intraoperatively, lateral retinacular release was performed in 3 knees. In the postoperative radiographic evaluation of patellar tracking, 10 knees (1.4%) had lateral tilting of the patella. The postoperative HSS scores were 93 (85-98). INTERPRETATION: The native femoral sulcus may be used as an effective and simple guide for the medial/lateral femoral component position.     

Lateral release for patellofemoral arthritis

Purpose: To determine the outcome of treatment of patients with symptomatic patellofemoral osteoarthritis by closed lateral patellar retinacular release. Type of Study: Retrospective study. Methods: Fifty patients who underwent 53 lateral retinacular release procedures between 1995 and 1999 for the treatment of symptomatic patellofemoral arthritis were assessed by questionnaire comprising the Oxford knee score, a visual analogue scale (VAS, 0-10) for pain, and questions relating to level of patient satisfaction. Patients were included in this study whether or not tibiofemoral arthritis was present, but lateral release was performed only in those for whom the anterior knee pain of patellofemoral arthritis appeared to predominate. Results: The average patient age was 53 years (range, 27 to 79 years). There were 14 men (28%) and 36 women (72%). Follow-up was a mean of 31 months (range, 12 to 65 months). Four patients underwent total knee replacement at 7, 14, 16, and 18 months after lateral release for recurrence of symptoms. In the remaining 49 knees, mean pain VAS was 3.8 ± 2.8. In 39 knees (80%), patients judged that they had experienced a reduction in pain compared with their preoperative state (2 were pain free), 8 (16%) were unchanged, and 2 (4%) were worse. The average Oxford knee score was 27 (range, 12-48). At follow-up, 33% of patients were very satisfied, 26% satisfied, and 41% dissatisfied with their knee. The presence of tibiofemoral disease did not affect any of the outcome measures. Two patients developed superficial infections of the arthroscopic port sites. There were no cases of hemarthrosis. Conclusions: Arthroscopic lateral release is effective in reducing the pain of symptomatic patellofemoral osteoarthritis and gives reasonable rates of patient satisfaction irrespective of the presence of tibiofemoral arthritis.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 4 (April), 2002: pp 399–403     

Total knee arthroplasty in valgus knees

One hundred thirty-four total knee arthroplasties in 98 patients with a valgus alignment were analyzed. Knees with a preoperative alignment of 10 degrees or greater anatomic valgus were believed suitable for inclusion. The average follow-up period in these patients was 4.5 years (range, two to ten years). One hundred eighteen knees were implanted with a posterior stabilized prosthesis, eight knees with a constrained implant design, four knees with a total condylar prosthesis, and four knees with a cruciate-retaining design. All components in all knees were cemented. A lateral retinacular release was necessary in 76% of the arthroplasties secondary to intraoperative lateral subluxation of the patella. The ligamentous release for balancing these valgus-deformed knees was done from the femur. There were 95 knees (71%) rated as excellent, 27 knees (20%) as good, eight knees (6%) as fair, and four knees (3%) as poor. Postoperatively, 76% of the knees had a tibiofemoral alignment between 5 degrees and 9 degrees valgus with an overall average of 7 degrees valgus (range, 3 degrees varus to 15 degrees valgus). Total knee arthroplasty is a reliable and durable procedure in the treatment of valgus knee arthritis. However, valgus-deformed knees represent a greater challenge than their varus counterparts to the implant surgeon in terms of the intraoperative balancing required. This may be a function of the greater difficulty in achieving ligamentous equilibrium and the relative rarity of valgus-deformed knees.     

Bicompartmental knee replacement and patellar resurfacing. A prospective study with a minimum follow-up of ten years.

We avoid routine patellar resurfacing during knee replacement because of the risk of major complications. We undertook a prospective study to evaluate the functional outcome of the patients who had no patellar resurfacing. Eleven patients (17 knees) who met the criteria for inclusion participated in the study. The preoperative diagnosis was osteoarthritis in all patients. A lateral retinacular release was performed when necessary. The knees were evaluated using the Hospital for Special Surgery knee scoring system. The mean follow-up was 10.5 years (range: 10 to 10.8 years). The average HSS score raised from 40 points to 83 points. The mean postoperative range of motion of the knee joint was 105 degrees. Postoperative radiographic evaluation revealed that there was no correlation between the integrity of the cartilage and the degree of pain. We concluded that patellar resurfacing is not a routine procedure in knee replacement when the diagnosis is osteoarthritis.     

Total knee arthroplasty in patients with isolated patellofemoral arthritis.

The current study evaluated the results of total knee arthroplasty for the treatment of isolated patellofemoral degenerative arthritis. Between 1980 and 1997, 31 total knee arthroplasties were done in 24 patients with advanced, isolated patellofemoral arthritis. The average followup was 5.2 years (range, 2-12 years). There was a significant improvement in the mean preoperative Knee Society pain and function scores. Twenty-one knees required a lateral retinacular release and three knees required additional formal proximal realignment at the time of the total knee arthroplasty. There were three reoperations in this series including, manipulation for poor motion in one patient; revision of a loose patellar component in one patient; and extensor mechanism realignment in the third patient. At midterm followup, total knee arthroplasty proved to be reliable and durable in alleviating pain and improving function in this group of patients with isolated, advanced patellofemoral arthritis. Surgeons should be made aware, however, that resurfacing of the patella and balancing the extensor mechanism for patients with isolated patellofemoral arthritis can be demanding technically as evidenced by the high rate of asymmetrically resurfaced patellas, the high rate of lateral retinacular release, and formal realignment procedures.     

Patellofemoral function after total knee arthroplasty: a comparison of 2 posterior-stabilized designs

Knee complications and function were analyzed in patients with 2 different posterior-stabilized total knee arthroplasty (TKA) designs, Optetrak 913 and Insall-Burstein II. Three hundred Insall-Burstein II knees with mean follow-up of 8 years (range: 5-9 years) and 300 Optetrak knees with mean follow-up of 6 years (range: 5-7 years) were studied. Lateral retinacular release was performed in 30% of Insall-Burstein II patients and 16% of Optetrak patients (P = 0.001), and patellar clunk was 4% for the Insall-Burstein II prosthesis and 0.3% for the Optetrak prosthesis (P = 0.003). No statistically significant differences in dislocation, fracture, or loosening rates were observed between the 2 groups. Knee Society scores were similar in 2 groups of 50 patients brought back to the office. Mean Knee Society knee scores were 92 and 94 for the Insall-Burstein II and Optetrak groups, respectively (P > 0.05), and function scores were 80 and 84 for the 2 groups, respectively (P > 0.05). At mid-term follow-up, Optetrak patients were less likely than Insall-Burstein II patients to require lateral retinacular release and experience patellar clunk.     

Optimising femoral component rotation using Equiflex instrumentation: a clinical review

Although there is agreement that flexion and extension spaces should be symmetrical and that rotation of the femoral component impacts outcome in a knee replacement, there is dispute over what is the 'correct' rotation and how best to achieve it (Akagi et al., Clin Orthop Relat Res 366:155-163, 1999; Anouchi et al., Clin Orthop Relat Res 287:170-177, 1993; Barrack et al., Clin Orthop Relat Res 392:46-55, 2001; Berger et al., Clin Orthop Relat Res 356:144-153, 1998; Jenny and Boeri, Acta Orthop Scand 75(1):74-77, 2004; Poilvache et al., Clin Orthop Relat Res 331:35-46, 1996; Siston et al., J Bone Joint Surg Am 87(10):2276-2280, 2005). Insall and Scuderi recommended placing a tensor in flexion and rotating the femoral cutting block so that its posterior edge is parallel to the cut tibia (Insall, Surgery of the knee, vol 2, 2nd edn., Churchill Livingstone, New York, 1993; Scuderi and Insall, Orthop Clin N Am 20:71-78, 1989). We feel Equiflex instrumentation will reliably achieve Insall and Scuderi's recommendation. To evaluate early results and lateral retinacular release rates using Equiflex instrumentation for TKR, we evaluated 209 consecutive knees (31 valgus, 178 varus) using this technique from 4 April 2005 until 19 September 2006. Pre and postop American Knee Society and Oxford scores, deformity, ROM, lateral retinacular release rates and complications were recorded. We could correct alignment and achieve our technical goals in 99% of cases. A lateral retinacular release was required in only five knees (2.4%). The complications are comparable to published data. The Equiflex instrumentation does help in equalising flexion-extension gaps, improves patellar tracking and reduces the incidence of lateral retinacular release.