Symptomatic bipartite patella: treatment alternatives

Bipartite patella is usually an asymptomatic, incidental finding. However, in adolescents, it may be a cause of anterior knee pain following trauma or a result of overuse or strenuous sports activity. Most patients improve with nonsurgical treatment. Surgery is considered when nonsurgical treatment fails. Excision of the fragment is the most popular surgical option, with good results. However, when the fragment is large and has an articular surface, excision may lead to patellofemoral incongruity. Lateral retinacular release and detachment of the vastus lateralis muscle insertion are other surgical options and are reported to produce good pain relief and union in some patients. These procedures reduce the traction force of the vastus lateralis on the loose fragment. Internal fixation of the separated fragment has limited support in the literature. Understanding the possible consequences of different treatment approaches to painful bipartite patella is necessary to preserve quadriceps muscle strength and patellofemoral joint function.     

Isometric contractions in the patellofemoral pain syndrome

Summary The role played by the vastus lateralis and vastus medialis obliquus in their alignment of the patella during maximal isometric quadriceps contractions was studied by electromyography in 28 patients with unilateral symptoms of the patellofemoral pain syndrome. Eleven knees were classified as subluxation of the patella and 17 as idiopathic chondromalacia patellae. The muscular activity pattern was the same in the two groups but decreased as compared with the contralateral nonsymptomatic knees. However, none of the groups revealed differences in the activity of vastus lateralis and vastus medialis obliquus suggesting muscular imbalance.     

Isometric contractions in the patellofemoral pain syndrome. An electromyographic study

The role played by the vastus lateralis and vastus medialis obliquus in their alignment of the patella during maximal isometric quadriceps contractions was studied by electromyography in 28 patients with unilateral symptoms of the patellofemoral pain syndrome. Eleven knees were classified as subluxation of the patella and 17 as idiopathic chondromalacia patellae. The muscular activity pattern was the same in the two groups but decreased as compared with the contralateral nonsymptomatic knees. However, none of the groups revealed differences in the activity of vastus lateralis and vastus medialis obliquus suggesting muscular imbalance.     

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.     

Anatomy of the junction of the vastus lateralis tendon and the patella

Forty-one knees from adult cadavera (twenty female and twenty-one male) were dissected to study the relationship between the longitudinal axis of the patella and the angles of insertion into it of the vastus lateralis and vastus lateralis obliquus muscles. The mean and variance in the angles of insertion of the vastus lateralis obliquus tendon were found to be significantly different between men and women (p less than 0.05 and p less than 0.01, respectively). Three distinct anatomical patterns in the insertion of the vastus lateralis obliquus muscle were delineated. The vastus lateralis muscle, particularly the vastus lateralis obliquus, creates an important lateral force-vector on the patella.     

The “Coiling-Up Procedure”: A Novel Technique for Extra-Articular Arthroscopy

The “coiling-up procedure” is a novel technique for extra-articular arthroscopy. A coil-shaped lifter is used to create the extra-articular working space, and a dry arthroscopy is performed. It can be combined with conventional intra-articular arthroscopy to enable direct vision from both inside and outside the joint. We have successfully used this technique to perform a vastus lateralis release in cases of painful bipartite patella. This is an innovative technique that offers the possibility of expanding the indications for extra-articular arthroscopy to other areas of the body. We describe in detail the technique for this new procedure in the knee.     

A comparison of outcomes at 2 to 6 years after acute and chronic anterior cruciate ligament reconstructions using hamstring tendon grafts

Purpose: To compare short- to intermediate-term outcomes of patients in whom an acute or chronic anterior cruciate ligament (ACL) reconstruction was performed with a hamstring tendon graft. Type of Study: A consecutive case series of patients who had 2-incision, arthroscopically assisted ACL reconstructions with a triple-strand hamstring tendon graft was retrospectively evaluated. Methods: A total of 120 patients were evaluated at a mean of 44 months. The Tegner Activity Scale, individual components of the Cincinnati Knee Rating System, and the modified Lysholm Score were administered to all patients. A total of 93 patients (78%) returned for examination, instrumented ligament laxity testing, radiographs, isokinetic strength testing, and completion of the IKDC Standard Knee Ligament Evaluation Form. Data from patients undergoing reconstructions for acute and chronic ACL deficiencies were compared. The acute group was defined as reconstruction within 6 weeks of injury without recurrent episodes of instability. Results: At surgery, significantly more (P <.05) cartilage abnormalities and partial medial menisectomies were found in the chronic group. At final follow-up, no significant differences (P >.05) were found between the acute and chronic groups for instrumented laxity, muscle strength, knee motion, or sports activity level. The acute group scored significantly higher (P <.05) on the Lysholm scale, Cincinnati Function scale, IKDC subjective assessment, and IKDC rating for pain at follow-up. The final IKDC grade resulted in significantly more (P =.039) normal knees for the acute group; however, 94.1% of acute and 92.9% of chronic knees were graded normal or nearly normal. Conclusions: Hamstring tendons are an excellent graft choice for ACL reconstruction in both acute and chronic injuries. According to the strict IKDC rating system, greater than 90% of all patients can be expected to have a normal or nearly normal knee at short- to intermediate-term follow-up; however, the chronic group will have fewer patients with a rating of normal.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 4 (April), 2001: pp 383–392     

Electromyographic investigation of unstable patella before and after its realignment operation

Background:

Patellar dislocations are either due to superolateral contracture of the soft tissue or imbalance of the power between the vastus medialis (VM) and the vastus lateralis (VL). The imbalance of muscle power as an etiology of patellar dislocation has not been studied. Hence, we studied the recurrent, habitual and permanent dislocations of the patella with an electromyogram (EMG) of the vastus medialis, vastus lateralis, and pes anserinus, before and after realignment operations, to document the muscle imbalance and effectiveness of the realignment operation.

Materials and Methods:

An electromyographic investigation was carried out on the vastus medialis and vastus lateralis in nine recurrent, 20 habitual, and 13 permanent dislocations of the patella, before and after their realignment operations. Pes anserinus transposition, which acted as a medial stabilizer of the patella, was also investigated with an EMG study, to understand its role on patellar stability at 0°, 30°, 60°, 90°, 120°, 150°, and full flexion of the knee. The age of the patients varied from nine to 30 (mean 15) years. There were 24 males and 18 females. Twenty-six patellar dislocations were on the right and 16 were on the left side.

Results:

Electromyographic pictures reveal subnormal activity of the vastus medialis in all types of dislocations and similar activities of the vastus lateralis in permanent and habitual dislocations recorded pre operatively, which recovered to almost normal values postoperatively, at the mean one-year follow-up. Pes anserinus, which was used for medial stabilization of the patella after its realignment, maintained normal EMG activity before and after the operation.

Conclusion:

This study is significant for understanding the imbalance of muscle activities in patients with an unstable patella, which can be rectified without recurrence after pes anserinus transposition.     

Long-term results of Alpina Postero-stabilized total knee replacement: 10- to 16-year follow-up

One hundred and ninety-four primary knee arthroplasties were done between 1992 and 1998 with Alpina Postero-Stabilized prosthesis. Eighty-eight knees were available for the long-term follow-up at a mean of 12?years. The mean IKS score improved from 103.1?±?21.9 points preoperatively to 161.5?±?25.6 at the latest follow-up (P?<?0.001). Eighty-four percent of the knees were rated good and excellent. The mean flexion significantly improved from 110° preoperatively to 117.5° at the latest follow-up (P?<?0.001). Two knees were revised: 1 due to infection and 1 due to femorotibial malalignment. Eight other knees were revised: 7 for isolated patella addition, 1 for patella replacement. Excluding patella failure, the 12-year Kaplan-Meier survivorship for the entire cohort was 98.8 (95% CI, 97.2–100%). Alpina Postero-Stabilized TKA showed good long-term results.     

Vastus medialis cross-sectional area is associated with patella cartilage defects and bone volume in healthy women

OBJECTIVES: Although vastus medialis and vastus lateralis are important muscular determinants of patellofemoral joint function, it is unclear how these muscles relate to the structure of the patellofemoral joint. The aim of this cross-sectional study was to determine the relationship between the vasti muscles and patella cartilage volume and defects and patella bone volume. METHODS: One hundred and seventy-five women, aged 40-67 years, with no knee pain or clinical lower-limb disease had magnetic resonance imaging (MRI) of their dominant knee. The cross-sectional areas of the distal vastus medialis and lateralis were measured 37.5mm superior to the quadriceps tendon insertion at the proximal pole of the patella. Patella cartilage volume and defects and patella bone volume were measured from these images using validated methods. RESULTS: There was no significant association between the distal vastus medialis cross-sectional area and patella cartilage volume. For every 1mm(2) increase in the distal vastus medialis cross-sectional area, there was an associated increased risk of patella cartilage defects [odds ratio (OR): 1.2; 95% confidence interval (CI) 1.004, 1.5; P=0.05], and an associated increase in patella bone volume (OR: 3.9; 95% CI 2.0, 5.8; P<0.001) after adjustment for potential confounders. There was no significant relationship between vastus lateralis cross-sectional area and measures of patella cartilage or bone. CONCLUSION: An increased cross-sectional area of the distal portion of the vastus medialis muscle is associated with an increased risk of patella cartilage defects, and an increase in patella bone volume among healthy women. Although these results need to be confirmed in longitudinal studies, they suggest that an increase in the distal vastus medialis cross-sectional area is associated with structural change at the patellofemoral joint.     

Surgical treatment of congenital dislocation of the patella

Eleven patients with 17 involved knees were surgically treated for congenital dislocation of the patella between 1978 and 1993. Ten patients with 13 involved knees followed up for a minimum of 2 years postoperatively composed the study group. Six patients had both involved knees operatively treated. In four patients, congenital dislocation of the patella was associated with a recognizable syndrome. All patients had fixed, painful lateral dislocation of the patella that could not be reduced. The average age at presentation was 7 years and 9 months (range, 2 months to 15 years). All patients underwent an extensive procedure including lateral release and advancement of the vastus medialis obliquus. Skeletally immature children underwent medial transfer of the entire patellar tendon. Skeletally mature patients underwent medial transfer of the tibial tubercle. Ten patients with 13 involved knees were followed up for > or = 2 years. Mean follow-up was 5.1 years (range, 1-17.5). At last follow-up, all patients reported a marked increase in activity tolerance and relief of pain. Average extension lag improved from 15 degrees before to 2 degrees after surgery. One superficial wound infection occurred; no patient developed a deep infection. One peroneal neurapraxia occurred but resolved with observation. Redislocation of the patella occurred in the immediate postoperative period in one patient. Operative treatment of congenital dislocation of the patella can predictably improve knee function when all aspects of the complex pathologic anatomy are addressed.     

The forces in the anterior cruciate ligament and knee kinematics during a simulated pivot shift test: A human cadaveric study using robotic technology

Purpose: Although it is well known that the anterior cruciate ligament (ACL) is a primary restraint of the knee under anterior tibial load, the role of the ACL in resisting internal tibial torque and the pivot shift test is controversial. The objective of this study was to determine the effect of these 2 external loading conditions on the kinematics of the intact and ACL-deficient knee and the in situ force in the ACL. Type of Study: This study was a biomechanical study that used cadaveric knees with the intact knee of the specimen serving as a control. Materials and Methods: Twelve human cadaveric knees were tested using a robotic/universal force-moment sensor testing system. This system applied (1) a 10–Newton meter (Nm) internal tibial torque and (2) a combined 10-Nm valgus and 10-Nm internal tibial torque (simulated pivot shift test) to the intact and the ACL-deficient knee. Results: In the ACL-deficient knee, the isolated internal tibial torque significantly increased coupled anterior tibial translation over that of the intact knee by 94%, 48%, and 19% at full extension, 15°, and 30° of flexion, respectively (P <.05). In the case of the simulated pivot shift test, there were similar increases in anterior tibial translation, i.e., 103%, 61%, and 32%, respectively (P <.05). Furthermore, the anterior tibial translation under the simulated pivot shift test was significantly greater than under an isolated internal tibial torque (P <.05). Under the simulated pivot shift test, the in situ forces in the ACL were 83 ± 16 N at full extension and 93 ± 23 N at 15° of knee flexion. These forces were also significantly higher when compared with those for an isolated internal tibial torque (P <.05). Conclusion: Our data indicate that the ACL plays an important role in restraining coupled anterior tibial translation in response to the simulated pivot shift test as well as under an isolated internal tibial torque, especially when the knee is near extension. These findings are also consistent with the clinical observation of anterior tibial subluxation during the pivot shift test with the knee near extension.Arthroscopy: The Journal of Arthroscopic and Related surgery, Vol 16, No 6 (September), 2000: pp 633–639     

Der sog. Midvastus-Zugang zur Implantation von Kniegelenkendoprothesen

Objective Approach to the knee for total knee arthroplasty with the goal to avoid tendency to lateralization and extension lag. Indications Implantation of total knee components. Revision surgery after total knee arthroplasty. Contraindications Morbid obesity. For revision surgery: preoperative knee flexion of < 60°. Surgical Technique Anterior midline incision, blunt separation of the distal part of the obliquely running fibers of the vastus medialis over an extent of at least 5 cm. The muscle incision ends at the proximal and medial corner of the patella and is continued distally along the medial patellar border ending at the tibial tuberosity. After opening of the joint, the patella is dislocated laterally thus exposing the articular surfaces. After insertion of the components, superficial adaptation of the muscle fibers and wound closure in layers. Results Of 297 total knee implants 276 knees (92.9%) could be followed up for an average of 36.2 (19–56) months. 153 knees were in women and 123 in men with an average age of 66.3 (33–81) years. In none of the operations a lateral release became necessary. The results were based on the score of the American Knee Society. The score showed 52.3 points preoperatively and 90.6 at follow-up. 95% of the patients had an excellent or good functional result. Tangential radiographs of the patella with the knee in 30° of flexion showed in 91% a central position in the patellar groove.     

Lateral facet syndrome of the patella. Lateral restraint analysis and use of lateral resection

Thirty-eight knees in 34 patients with an average age of 22 years were diagnosed as having lateral facet syndrome (LFS), a painful compressive arthropathy of the lateral facet of the patella. This diagnosis was based on the physical findings of tenderness at the lateral patellofemoral joint line, tenderness over the vastus lateralis obliquus (VLO) tendon just above the patella, a positive medial apprehension test, and marked resistance to medial patellar displacement with the knee flexed 30 degrees. The most common complaints were patellar pain with activity, pain with prolonged knee flexion, intermittent knee swelling, and giving way. At surgery, the VLO, the lateral retinaculum (LR), and the anterior fibers of the iliotibial tract (ITT) were sequentially divided from the lateral border of the patella. Each was temporarily reattached to a cuff of soft tissue left on the patella using surgical clamps to determine its contribution to lateral restraint. The VLO was found to be the primary restraint in one-half of the knees. In one-third of the knees, all three of the structures contributed equally. In six knees, the primary restraint was the anterior fibers of the ITT, whereas the LR was the primary restraint in only two. The distal ends of these three structures were then resected to prevent rescarring and retethering. At a minimum follow-up period of two years, 87% had satisfactory relief of their patellar pain, had returned to normal activities, and had no or minimal physical findings of LFS. The procedure is recommended for patients who have failed other procedures and in those whose symptoms cannot be controlled by activity modification, exercises, bracing, or medication.     

Chondral and osteochondral injuries associated with acute patellar dislocation

Purpose: The purpose of this study was to evaluate the frequency and precise pathology of articular cartilage injuries after acute patellar dislocation. Type of Study: Case series. Methods: In 39 consecutive knees with initial lateral patellar dislocation, the articular cartilage injuries were examined using arthroscopy or macroscopic observation. Results: Thirty-seven knees (95%) had articular cartilage injuries of the patellofemoral joint and 2 knees (5%) had no cartilage injury. In all 37 knees (95%), articular cartilage injuries were observed in the patella. The appearances were categorized into 3 groups: cracks alone (9 knees), cartilage defect caused by osteochondral or chondral fracture (7 knees), and cartilage defects caused by osteochondral or chondral fracture associated with cracks (21 knees). The main site of osteochondral fracture was the medial facet, and the main site of cracks was the central dome. Twelve knees (31%) had cartilage injury of the lateral femoral condyle. Conclusions: From this study, articular cartilage injuries, especially of the patella, seem to be common occurrences after acute patellar dislocation. Chondral and osteochondral injuries of the patella were classified into 3 groups.     

The quadriceps function in patellofemoral disorders

Summary The influence of quadriceps contraction on patellar alignment was investigated in tangential views of 31 patients with patellofemoral complaints and compared with 25 controls. The congruence angle decreased significantly following quadriceps contraction in patients with patellar subluxation in contrast to those with chondromalacia and normals. Electromyography (EMG) of the vastus lateralis (VL) and vastus medialis obliquus (VMO) during maximal quadriceps contraction was obtained prior to and after 3 months of isometric quadriceps exercises in 15 knees with patellar subluxation and in 11 with idiopathic chondromalacia of the patella. The EMG after 3 months revealed an increase in the activity of both VL and VMO only in patients with patellar subluxation, but the muscular balance of the patella remained unchanged. Only seven patients were improved after 3 months. A more selective training of the VMO is proposed.

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Zusammenfassung Der Einfluß der Quadricepsmuskelkontraktion auf die Führung der Patella wurde bei 31 Patienten mit Beschwerden im Femoropatellargelenk (Subluxation der Patella, idiopathische Chondromalacia patellae) untersucht. Als Kontrolle dienten 25 beschwerdefreie Personen. Röntgenologisch zeigte sich bei Patienten mit Subluxation der Patella der Patellakongruenzwinkel im Vergleich zu Normalpersonen und Patienten mit Chondromalacia patellae abgeflacht. Der Unterschied war statistisch signifikant. Die elektromyographische Aktivität des M. vastus lateralis and des M. vastus medialis obliquue stieg nach 3monatigem intensiven Muskeltraining le diglich bei Patienten mit Subluxation der Patella an, wobei jedoch die muskuläre Balance unverändert blieb. Das Beschwerdebild war jedoch nur bei 7 Patienten gebessert. Es wird daher ein selektives Training des M. vastus medialis obliquus empfohlen.

     

Delayed proximal repair and distal realignment after patellar dislocation

Twenty athletes with distal malalignment who sustained unilateral traumatic patellar dislocation remained impaired by chronic instability. Surgery was performed at a mean age of 18 years. Posttraumatic attenuation of the medial patellofemoral ligament was repaired near the margin of the patella in 10 knees and avulsion or attenuation posterior to the vastus medialis obliquus in 10 knees. Advancement of the medial patellomeniscal ligament at the margin of the patella and normalization of the Q angle to 10 degrees by tibial tubercle osteotomy were performed in each knee. Distal lateral retinacular release without release of the normal vastus lateralis tendon was performed. Results were judged according to Turba et al, and activity levels were evaluated per guidelines of the International Knee Documentation Committee. Eighteen (90%) patients achieved good or excellent results and were unimpaired at a minimum of 24 months. Two patients achieved fair subjective results with some impairment in vigorous activity. There was no recurrent instability. Radiographically, the mean preoperative patellofemoral congruence angle improved from 20 degrees to 0 degree. Athletes who sustain an initial traumatic patellar dislocation after physeal closure and in whom conservative management fails can be treated successfully by repair of the medial patellofemoral ligament at the site of disruption and advancement of the medial patellomeniscal ligament combined with correction of an elevated Q angle.     

The effectiveness of the use of electrocautery with chondroplasty in treating chondromalacic lesions: A randomized prospective study

Purpose: To determine the clinical effect of electrocautery with arthroscopic chondroplasty on chondromalacic tissue. Type of Study: A randomized, prospective study. Methods: In a prospective study, 146 patients were randomly placed in either a control group (chondroplasty alone) or a treatment group (chondroplasty and electrocautery). Intraoperative findings in both treatment and control groups were classified by both the extent of chondromalacia and the number of compartments in which chondromalacia was diagnosed. In our study, we used 6 defined compartments: medial and lateral tibial plateau, medial and lateral femoral condyles, patella, and femoral trochlea. Patients were followed up at 1 year and evaluated using the Lysholm scale. Postoperative Lysholm scores were matched against compartment involvement and compared between groups. Results: There was no significant difference in the patients with grade 2 chondromalacia in either control or cautery group (P >.5). Groups with grade 3 chondromalacia showed a significant difference favoring the control group (P <.05). A significant difference was found in comparing 2-compartment chondromalacia between the 2 treatment cohorts, again, favoring the control group (P =.01). The remaining groups of multiple compartment chondromalacia showed no significant difference, indicating that the postoperative result was independent of the use of electrocautery. Conclusions: This study shows that electrocautery as an adjunct to chondroplasty offers little benefit in the treatment of chondromalacic lesions and may, in fact, limit successful outcome.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 2 (February), 2002: pp 190–193     

The effect on leg strength of tourniquet use during anterior cruciate ligament reconstruction: A prospective randomized study

Purpose: The purpose of this study was to prospectively evaluate the effect of tourniquet use during endoscopic anterior cruciate ligament (ACL) reconstruction surgery on dorsiflexion strength, plantarflexion strength, quadriceps strength, and calf and thigh girth. Type of Study: The study was a prospective, double-blind, randomized clinical trial. Methods: Forty-eight patients were prospectively randomized into 2 groups: (1) tourniquet use during surgery (T) and, (2) no tourniquet use during surgery (NT). Within 1 week before ACL reconstruction, all patients were evaluated for isometric plantarflexion and dorsiflexion strength, thigh strength, and thigh and calf girth. These same measurements were repeated 3 weeks postoperatively. At 6 months, isokinetic quadriceps strength was evaluated at 60° per second. All patients underwent ACL reconstruction using a patella-tendon autograft and a tourniquet was placed on the affected extremity. In all 25 T patients, the tourniquet was inflated to 300 mm Hg. The average tourniquet time was 85 ± 7 minutes (range, 51 to 114 minutes). Results: ACL reconstruction resulted in a significant decrease in thigh girth (P <.01), calf girth (P <.01), dorsiflexion strength (P <.01), and plantarflexion strength (P <.05) at 3 weeks postoperatively in both groups. The T group had a greater decrease in thigh girth than the NT group (P <.05). Tourniquet use did not have an effect on calf girth (P =.53), dorsiflexion strength (P =.17), or plantarflexion strength (P =.32) at 3 weeks postoperatively. Tourniquet use also had no effect on quadriceps strength at 6 months postoperatively (P =.78). Conclusions: Tourniquet use of less than 114 minutes during ACL reconstruction had no effect on the strength of the lower extremity after surgery.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 6 (July-August), 2001: pp 603–607