Navigation-assisted less invasive total knee arthroplasty compared with conventional total knee arthroplasty: a randomized prospective trial

The purpose of this study was to evaluate the hypothesis that a less invasive (LIS) surgical technique using a navigation system would promote rapid recovery and improve alignment compared with conventional technique in total knee arthroplasty (TKA). This study compared 49 navigation-assisted LIS TKAs with 53 conventionally performed TKAs using a medial parapatellar arthrotomy with patellar eversion. Navigation-assisted LIS TKA used a shorter skin incision, a midvastus approach without patella eversion, and a navigation system. Navigation-assisted LIS TKA had better pain scores, shorter times to achieve 90 degrees flexion and straight leg raise, and a smaller extension lag during the very early postoperative period. However, there were no differences between the groups 2 weeks postoperatively. There were no differences in mean prosthetic alignment between the 2 groups, but the navigation-assisted LIS group had fewer "outliers" than the conventionally performed TKA group.     

Electromyographic evaluation of the midvastus approach

Compared with the standard median parapatellar approach, the muscle-splitting midvastus approach to the knee has led to claims of an easier and earlier recovery after total knee arthroplasty, but some investigators have questioned whether the midvastus approach damages the vastus medialis obliquus. We used electromyographic and nerve conduction studies to evaluate whether we could document any such damage. Twenty patients undergoing bilateral total knee arthroplasty were randomized prospectively for the treatment of 1 knee with each of the 2 approaches. Radiographs, electromyographies, nerve conduction studies, range-of-motion tests, and Knee Society function and pain tests were conducted preoperatively and at 6 weeks postoperatively. If the electromyography or nerve conduction tests were abnormal at 6 weeks, the tests were repeated at 12 weeks. At the final follow-up, these studies showed no evidence of muscle denervation. The midvastus approach appears to be a safe alternative for knee arthrotomy for total knee arthroplasty without concerns for damage to the vastus medialis obliquus.     

Effects of a Less-invasive Surgical Technique on Cement Mantle Quality in Total Knee Arthroplasty

The purpose of this study was to assess the effects of a less-invasive midvastus exposure during total knee arthroplasty (TKA) on cement mantle grade compared with a standard parapatellar arthrotomy and standard TKA. Fifty consecutive cemented minimally invasive TKAs using a midvastus approach, patellar subluxation without eversion, and less-invasive instrumentation were compared radiographically with a control cohort of 50 consecutive cemented standard TKAs. To eliminate patient selection bias, the standard cohort included consecutive surgeries completed before 2004, prior to the advent of minimally invasive techniques in TKA. Analog supine anteroposterior and lateral radiographs were evaluated using Ewald's criteria. Lucent lines, cement voids, and cement debris were recorded for each group.Radiographic analysis revealed compromised femoral component cement mantle grades in the minimally invasive group. The number of anterior femoral cement voids (zone 1) was significantly higher in the minimally invasive group, and peripatellar and tibial cement debris was also more common in the minimally invasive group. Based on these findings, the midvastus approach compromises the surgeon's ability to duplicate a consistent femoral cement mantle obtained using a standard exposure.     

Sonographic imaging of the patellofemoral medial joint stabilizing structures: findings in human cadavers

The medial soft-tissue restraints of the patella, specifically the medial patellofemoral ligament and the vastus medialis obliquus muscle, are critical to patellofemoral joint stability. A reliable and inexpensive imaging technique would be clinically useful especially after acute patellar dislocation. The medial patellofemoral ligament and the vastus medialis obliquus muscle were identified in cadaveric dissection. The attachments of the medial patellofemoral ligament to the patella and the adductor tubercle, and the attachments of the vastus medialis obliquus muscle to the adductor magnus tendon, adductor tubercle, and patella were carefully observed. Sonography then was performed on four thawed fresh frozen cadaver knees. After sonographic examination of these structures, the knees were dissected and the structures previously identified by sonography were verified. In all four specimens, these restraints of the patellofemoral joint were identified by sonography based on their imaging characteristics and surrounding bony and soft-tissue landmarks.     

Patellar Eversion Does Not Adversely Affect Quadriceps Recovery Following Total Knee Arthroplasty

Although avoiding patellar eversion during a total knee arthroplasty (TKA) has theoretical benefit in quadriceps recovery, there has been paucity of supportive objective clinical results. We prospectively designed the study whether TKA without patellar eversion has better quadriceps recovery in an objective, dynamometer study. Seventy-two knees undergoing TKA with midvastus approach were randomized into two groups according to patellar eversion or not. Clinical data and objective quadriceps recovery using a dynamometer were investigated preoperatively and postoperative at 6 weeks, 3 months, 6 months and 1 year. There were no statistical differences between two groups throughout the follow-up periods in recovery of quadriceps force or power and clinical data. Choosing to evert patella during TKA using midvastus approach would not adversely affect postoperative quadriceps recovery.     

Quantitative study of the quadriceps muscles and trochlear groove geometry related to instability of the patellofemoral joint

This was a quantitative study of the major anatomical structures associated with instability of the patellofemoral joint: the quadriceps muscles and the femoral trochlear groove. The attachments of the muscles to the patella, their lines of action, and their relative sizes (physiological cross-sectional areas) were found. On the basis of the physiological cross-sectional areas, it was estimated that the central muscles—the rectus femoris and vastus intermedius—contributed 35% of the quadriceps strength, with 40% from the vastus lateralis and 25% from the vastus medialis. The vastus lateralis had the most variable results, with the ratio of the lateralis to the medialis ranging from 0.90 to 2.18; this may be associated with patellar instability. Both the long and oblique parts of the vastus medialis were more oblique than the corresponding parts of the vastus lateralis. Photographic “skyline” views of the trochlear groove produced data on the sulcus angle and ratio of depth to width. The data showed that the trochlear groove did not deepen in the area contacted by the patella with progressive knee flexion (p > 0.53). contrary to popular belief. These data are useful for objective analysis of patellofemoral stability and related surgical interventions.     

Insall Proximal Realignment of the Patella for Recurrent Dislocation or Subluxation

Objective

Proximal realignment of the patella for the treatment of patellar subluxation or dislocation consisting of a lateral release and advancement of the vastus medialis.

Indications

Recurrent lateral subluxation or dislocation of the patella despite a supervised exercise program. Recurrent subluxation or dislocation of the patella.

Contraindications

Congenital dislocation of the patella. Generalized degenerative arthritis of the patellofemoral joint. Excessive valgus deformity of the knee. Moderate to severe muscular atrophy of the vastus medialis muscle (i.e., in neurologic disorders).

Surgical Technique

Lateral parapatellar incision of skin. Detachment of the fibers of the iliotibial tract and the lateral retinaculum from the lateral patella. Medial capsular incision extending from the quadriceps tendon over the patella into the patellar ligament. The quadriceps expansion is shaved from the medial third of the patella preserving the longitudinal continuity. The vastus medialis is advanced and sutured onto the middle and distal aspects of the patella.

Results

Out of 21 patients (16 women, five men) who received a proximal realignment procedure during 1989 and 1993, all could be evaluated after 6.3 years (minimum follow-up of 4 years 5 months, maximum of 8 years 3 months). In 13 patients the diagnosis was recurrent dislocationof the patella, in eight patients a true primary traumatic dislocation was noted. A generalized ligamentous laxity was seen in three patients. One patient had a superficial wound infection postoperatively. Two patients had an excellent, 13 patients a good, six patients a fair and no patient a poor result according to the subjective score of Turba et al. Three patients experienced a recurrence of instability (one to three events) after the operation. One of these patients had to be revised for postoperative recurrent dislocation of the patella. The other two patients experienced no more symptoms of instability after muscle strengthening exercises of the vastus medialis muscle.     

The composite vastus medialis-patellar complex osseomuscular flap as a salvage procedure after complex trauma of the knee--an anatomical study and clinical application.

BACKGROUND: In the setting of severe perigenicular trauma or complicated endoprosthetic knee surgery, primary knee fusion may be the last resort for salvage of the limp. In this case, the patella looses its destination as an anterior knee stabilizer and can become a substantial donor of bone substance, especially if osseous defects are involved. PATIENTS AND METHODS: 12 formalin fixated cadavers were studied in terms of vascular anatomy, pedicle reliability, arc of rotation and their relation to sex, age, and height. Moreover, the operation was performed on a suitable patient. RESULTS: The quadriceps with the vastus medialis and the patella can be raised from the tibial tuberosity up to the entrance of the osteoarticular branch of the superficial femoral artery into the vastus medialis muscle ca 16 cm (15-19 cm) from the inferior patellar pole. This distance correlated well to the overall height of the cadavers (P=0.009). The vascular prerequisites were always present. In the clinical case, there was a favorable outcome with knee fusion after 4 months, despite of the lateral condylar defect. DISCUSSION: The composite vastus medialis-patellar complex osseomuscular flap can be safely used as a source of vascularized femoral condyle substitute in the setting of primary knee fusion.     

Low-tech rehabilitation of bilateral patellofemoral knee pain in a runner: a case study

Patellofemoral pain is a common ailment within both the running and general populations. Many of the structures of the anterior knee that comprise the patellofemoral joint can be the source of chronic pain and inflammation that is associated with this condition. Much of the evidence in the literature points to a delay in activation of the vastus medialis oblique muscle as compared to the vastus lateralis, vastus medialis weakness, and ultimately faulty patellar tracking as the chief causative factors in the development of patellofemoral pain. This is a single case study of a 51-year-old recreational runner with an 18-month history of bilateral patellofemoral knee pain. Treatment included the use of low-tech in office rehabilitation strategies known to affect those causative factors responsible for patellofemoral pain. Evidence based treatment modalities were utilized in combination, which included patellar mobilization, spinal manipulation, proprioceptive and strength training, and semi-rigid orthotic use, to effect vastus medialis oblique vs. vastus lateralis activation, vastus medialis strength, and patellar movement. The patient responded very well to a 12 week course of treatment and resumed recreational running with minimal to no pain at the six month, one and two year follow-ups.     

Surgical treatment of habitual dislocation of the patella in childhood

Surgical Principles Medial displacement of the medial half or the medial two thirds of the patellar ligament on the proximal tibia; the detached ligament is anchored to a chiselled trough in the bone with a cancellous bone screw and serrated washer. Division of the fibres of the tractus iliotibialis leading into the patella and of the lateral extensor retinaculum up to the vastus medialis (so-called “lateral release”). Transfer of the vastus medialis in lateral and distal direction by approximately 1 to 1.5 cm onto the patella. Double breasting of the medial extensor retinaculum. First published in: Operat. Orthop. Traumatol. 1 (1989), 94–99 (German Edition).     

Anatomical assessment of the vastus medialis oblique muscle in patients with osteoarthritis of the knee

Minimally invasive total knee arthroplasty requires subluxation of patella laterally without eversion. The anatomy of the vastus medialis oblique muscle (VMO), which affects the surgical exposure of minimally invasive total knee arthroplasty, was investigated. There was no significant difference between men and women with respect to any parameter. The average fiber angle relative to the rectus femoris muscle was 52.9 degrees on anteroposterior view and 49.7 degrees on lateral view. The average insertion height and the distal portion of VMO belly were 17.3% and 38.4% of the patella length from the upper pole of patella, respectively. Female patients had lower VMO attachment and VMO belly, and a significant sex difference was demonstrated. All patients had attachments beneath the upper pole of the patella.     

A midvastus muscle-splitting approach for total knee arthroplasty

This study presents a modification of the medial parapatellar surgical approach for total knee arthroplasty. This approach separates the vastus mediatis muscle in the direction of its fibers beginning at the superior pole of the patella. One hundred eighteen consecutive total knee arthroplasty cases, performed by a single surgeon, were randomized prospectively to receive a medial parapatellar or midvastus muscle-splitting surgical approach. The frequency of lateral retinacular releases was recorded, patellar tilt and translation were measured, and quadriceps strength was tested. The midvastus muscle-splitting approach provided excellent exposure to all knees. Patellar stability and quadriceps strength were equivalent for the two approaches. It is concluded that the midvastus muscle-splitting approach is an efficacious alternative to the medial parapatellar approach for primary total knee arthroplasties.     

Distal Disinertion of the Patellar Ligament Combined with Avulsion Fractures at the Medial and Lateral Margins of the Patella a Case Report and an Experimental Study

A 12-year-old boy presented with a proximally retracted patella 5 months after an injury to the left knee. The clinical and radiographic features and the findings at operation led to the conclusion that the original lesion had been a distal disinsertion of the patellar ligament combined with avulsion fractures at the medial and lateral margins of the patella, produced by the medial and lateral longitudinal patellar retinacula. Loading experiments on amputation and cadaver specimens showed that these retinacula, apart from being tendons for the vastus medialis and the vastus lateralis, respectively, constitute a direct fibrous connection of considerable strength between the patella and the tibia and thus are capable of producing avulsion fractures.     

EMG Biofeedback as Treatment for Patellofemoral Pain Syndrome*

Patellofemoral pain syndrome may be classified as a dysfunction of the patella's ability to track in the femoral groove. This study identifies an effective treatment approach for patellofemoral pain syndrome. The approach integrates the concept of improved patellar tracking through selective enhancement of the vastus medialis oblique muscle with conventional exercise regimens for patellofemoral pain syndrome. Six patellofemoral pain syndrome patients were enrolled in a three-phase electromyographic biofeedback and exercise program: 1) biofeedback orientation and instruction in isometric quadriceps contractions, straight leg raises, and a home program; 2) biofeedback training for vastus medialis oblique enhancement with isometric quadriceps contractions, straight leg raises, terminal knee extensions, and progressive resistive exercises; and 3) incorporation of increased vastus medialis oblique activity in functional patterns of movement. All six patients learned to alter their vastus medialis oblique activity through the use of this treatment approach. The alteration of vastus medialis oblique activity resulted in an apparent change in the patellofemoral forces and a concomitant decrease in the patients' complaints of pain. These patients were able to return to pain-free functional activities in only six to nine treatment sessions within a 4- to 6-week period. The use of electromyographic biofeedback coupled with a graded exercise program is an efficient and effective treatment approach for patellofemoral pain syndrome patients.J Orthop Sports Phys Ther 1984;6(2):95-103.     

A prospective comparative study of the midvastus and medial parapatellar approaches for total knee arthroplasty in the early postoperative period

Introduction  

The commonest surgical approach for total knee arthroplasty is medial parapatellar approach. This involves splitting the quadriceps tendon and disrupts the extensor mechanism and this may potentially weaken it. The midvastus approach involves splitting the vastus medialis muscle instead of entering the quadriceps tendon; therefore, minimising interruption of the extensor mechanism without compromising the exposure of the knee.     

髌腱内移和髌内侧筋膜肌肉瓣外移治疗先天性髌骨脱位

目的评价髌腱内移和髌内侧筋膜肌肉瓣外移术治疗先天性髌骨脱位的效果。方法自1994年6月～1998年6月,采用髌腱内移和内侧筋膜肌肉瓣外移的方法治疗先天性髌骨脱位5例,男2例,女3例,平均年龄7岁(4～10岁)。4例为单侧髌骨脱位,1例为双侧(只治疗一侧),均未合并其它畸形。结果术后随访1.5～5年,平均3年,无手术并发症,无术后再脱位和半脱位。4例膝关节能完全伸直,1例差10°;2例膝外翻消失;1例10岁女童术后出现髌骨低位,但膝外翻消失、功能正常且伸膝有力。结论先天性髌骨脱位是一种持续、不可复性脱位,需手术治疗。髌内侧筋膜肌肉瓣外移和髌腱内移术操作简单,损伤较小,并发症少,效果优良,是一种值得推荐的手术方法。     

髌骨半脱位70例治疗分析

目的探讨髌骨半脱位的治疗方法及其预后。方法回顾性分析70例（130膝）髌骨半脱位患者的临床资料,其中男30例,女40例;年龄10～48岁,平均23岁。患者髌骨的形态均为WibergⅡ、Ⅲ型,其中伴有外侧髌股关节骨关节炎者58例108膝,高位髌骨23例46膝,外伤后股四头肌内侧头肌张力不良10例10膝。Q角20°～40°。全部行手术治疗,手术方式包括：髌外侧支持带充分松解（130膝）;髌内侧支持带紧缩、股内侧肌移位至髌骨前内侧（12膝）;髌骨外侧部分切除（17膝）;胫骨结节前、内侧移位（46膝）,平均内移1．0cm、前移1．2cm;缝匠肌前移（11膝）,半腱肌前移（13膝）;关节镜下髌外侧支持带松解,髌内侧支持带紧缩（31膝）。术中见全部病例髌外侧支持带均明显增厚。结果随访3～180个月,根据Insall等评分系统评估分析疗效,术后疗效优78膝,良33膝,可12膝,差7膝。患者术后疼痛、关节活动功能均得到明显改善,尤其是解除膝前痛效果显著。结论根据病因及病理改变选择恰当的手术方式治疗髌骨半脱位均可取得满意的效果,特别是关节镜手术具有创伤小、恢复快的特点,值得进一步推广应用。     

A technique of staged lateral release to correct patellar tracking in total knee arthroplasty

Optimal patellar tracking and component alignment are important in achieving a well-functioning total knee arthroplasty (TKA). The patella is constrained partly by design of the prosthetic trochlear groove, and patellar tracking is governed by a combination of static and dynamic factors. Maltracking may result from excessive or unbalanced tension in the surrounding soft tissues. This article describes a staged progressive lateral release of the patellar retinaculum in TKA, which is classified into 6 stages. Stage 1 transects the deep lateral patellofemoral ligament; stages 2 to 6 extend the lateral patellar incision distally from vastus lateralis to the tibial tubercle. This technique was used in a series of 96 primary TKAs. We report the rates of the various stages of lateral release and the variables that might affect the decision to perform such a release.     

Variation of the vastus medialis obliquus insertion and its relevance to minimally invasive total knee arthroplasty

The aim of the study was to assess population variation of the vastus medialis obliquus (VMO) insertion to the patella. Sixty-five magnetic resonance imaging studies and 18 cadaver specimens were studied. The VMO insertion was expressed as a percentage of patellar length. In the magnetic resonance imaging cohort, the mean insertion was 51% (range 13-95); 59% (38 of 65) of individuals had an insertion within 40% to 60%, with 25% (16 of 65) being distal to 60%. In the cadaveric study, mean insertion was 52% (range 26-81). Both groups displayed a Gaussian distribution. Laterality and sex had no effect upon the level of insertion. The VMO has a variable and frequently distal insertion that may preclude a true quadriceps-sparing approach during minimally invasive knee arthroplasty.