Lower limb asymmetry and patellofemoral joint incongruence in the etiology of knee exertion injuries in athletes

The association between different knee exertion injuries and lower limb malalignments was studied in 121 male athletes with knee exertion injuries and in 20 male athletes without knee symptoms. The associations between different malalignments was also analyzed. Leg length inequality (LLI), knee valgus, and different indexes of patellofemoral joint congruence were measured using radiological methods. Male athletes with patellar apicitis (n = 59) had significantly more LLI (P less than 0.001) and patella alta (P less than 0.05) than athletes without knee symptoms. The knee valgus was of the same numerical value in the shorter and longer leg sides in subjects with LLI of at least 5 mm (n = 58). A positive correlation was found between lateral patellar displacement (LPD) and patella alta (LT/LP) (P less than 0.001). Negative correlations were found between the sulcus angle (SA) and the lateral patello-femoral angle (LPA) (P less than 0.001) as well as between the LPD and the LPA (P less than 0.001).     

The height of the patella: an anatomical study

The anterior region of the left knee joint of fifty fresh human cadavers (37 males, 13 females) was dissected and the following measurements were carried out: length of the patella (LP), width of the patella (WP), length of the patellar tendon (LT), and width of the patellar tendon (WT). The ratio LT/LP for assessment of the vertical position of the patella was 1.00 (range 0.72-1.38; SD 0.14) and found to be in full agreement with radiographic studies carried out first by Insall and Salvati in 1971 and later by other authors. There was no significant statistical difference between the Insall-Salvati index in males and females. The length and width of the patella as well as the length of the patellar tendon were found to be significantly larger in males than in females (P less than 0.001).     

Radiographic clues to the unstable knee: are findings of trochlear dysplasia on lateral knee radiographs reliable and predictive of patellar dislocation?

Emergency Radiology - Trochlear dysplasia (TD) is a key predisposing risk factor for patellar instability (PI) and lateral patellar dislocation (LPD) injuries. It is useful to understand the...     

Cine MR imaging before and after realignment surgery for patellar maltracking — comparison with axial radiographs

Objective Comparison of motion-triggered cine magnetic resonance (MR) imaging and conventional radiographs for the assessment of operative results of patellar realignment.Subjects and methods Fifteen patients with recurrent patellar dislocation or patellar subluxation were evaluated with conventional axial radiographs before and after realignment surgery by measuring the congruence angle (CA), lateral patellofemoral angle (LPFA), and lateral displacement (d). In eight patients the patellofemoral joint was additionally evaluated pre- and postoperatively with motion-triggered cine MR imaging by determining the bisect offset (BSO), lateral patellar displacement (LPD), and patellar tilt angle (PTA).Results and conclusions Significant differences between the pre- and postoperative measurements were found for all MR imaging parameters (BSO, LPD, PTA: p<0.01) but not for the conventional X-ray parameters (CA: p=0.70, LPFA: p=0.56; d: p=0.04). Motion-triggered cine MR imaging was superior to conventional tangential radiographs for assessing the effectiveness of patellar realignment surgery.     

Magnetic resonance imaging of patellofemoral relationships

Patellofemoral relationships were analyzed in 11 patients (13 knees) with patellar dislocation and 15 asymptomatic subjects (15 knees) at 0° and 20° of flexion. The measurements were made from five consecutive axial images through the patellofemoral joint. The six indices measured were lateral patellar tilt (LPT), lateral patellofemoral angle (LPA), lateral patellar displacement (LPD), patella-lateral condyle index (L/PW), congruence angle (CA), and sulcus angle (SA). The reproducibility of the method was evaluated. The difference between the two study groups was more evident at 0° than at 20° of knee flexion. Significant differences were noted between measurements made at different levels of the joint, particularly in the controls. Isometric contraction of the quadriceps muscle lateralized and tilted the patella slightly in both groups. L/PW with and without quadriceps muscle contraction, and LPA with reference to the anterior condyles differentiated between the two study groups most clearly. LPT and LPA with reference to the anterior condyles differentiated the study groups better than LPT and LPA with reference to the posterior condyles. The reproducibility was good except for inter-observer comparison of CA and SA. The use of an imaging plane selected at the midpoint of the patellar articular cartilage increases the sensitivity of the measurements, since it takes into account both the height of the patella and the tendency towards lateralization. These results indicate that patellar tilt is best measured with the LPA index and patellar lateralization with the L/PW index at 0° knee flexion. This study should always include isometric contraction of the quadriceps muscle.     

Full arthroscopic lateral retinacular release with hook knife and quadriceps pressure-pull test: long-term follow-up

The most important causes of anterior knee pain include patellofemoral malalignment which causes patella–condyle contact anomalies at the patellofemoral joint, excessive patellar lateral pressure increase, trauma and overuse. In this article, besides presentation of late clinical results of 169 lateral retinacular release cases which were surgically treated between January 1995 and December 2002 with the help of a hook knife from the anterolateral portal due to lateral compression syndrome and patellar maltracking, we also described quadriceps tendon pressure-pull test which strongly indicates patellofemoral pain during physical examination of a patient with anterior knee pain. In addition to radiological patellofemoral imaging methods, we describe dynamic arthroscopic patellofemoral joint examination which is applied perarthroscopically to all of our surgically treated patients. We divided the patients into two groups: group 1 was the younger group with age 16–40 years; group 2 was the older group with age >41 years. Preoperative mean Lysholm scores for group I was 67.6 and 98.6, postoperatively, whereas it was 62.3 preoperatively and 91.4 postoperatively in group 2. This improvement of Lysholm scores postoperatively was statistically significant for each of the two groups (p=0.001). For group 1 preoperative IKDC scores were A in 8 patients, B in 61 patients and C in 11 patients, whereas it was A in 78 patients and B in 2 patients postoperatively. For group 2 preoperative IKDC scores were A in 2 patients, B in 43 patients, C in 36 patients and D in 8 patients, whereas it was A in 78 patients and B in 11 patients. This improvement of IKDC scores postoperatively was also statistically significant for each of the two groups (p=0.001). Preoperative and postoperative congruens angles of all patients were also measured. Preoperative mean congruens angle was +16.4 in group 1 while mean congruent angle was –7.1 postoperatively. For group 2 preoperative mean congruens angle was +18.7 preoperatively and –6.9 postoperatively. This improvement was statistically significant for each of the two groups (p=0.001). The overall number of patellar lateral compression syndrome cases were 51 (24 in group 1, 27 in group 2), patellar lateralization cases were 64 (28 in group 1, 36 in group 2) and patellar subluxation cases were 54 (28 in group 1, 26 in group 2). At the evaluation of arthroscopic lateral patellar facet and lateral femoral condylar chondral pathologies, we statistically showed that patellar chondral pathologies were more severe than the femoral chondral pathologies (p=0.001). In our opinion, the severity of patellar lateral facet chondral lesions, although it has a thicker layer of cartilage, is due to distribution of load to a larger contact area of lateral femoral condyle [1, 2]. Statistically increasing severity of femoral (Kendalls tau-b: 0.248, p=0.001) and patellar chondral lesions (Kendalls tau-b: 0.444, p=0.0001) with age is compatible with our arthroscopic and clinical observations. The most important complication seen in our cases was fibrosis at the site of lateral release, seen in three patients. They were healed without any sequela with local corticosteroid injection into the fibrosis tissue. We did not see any hemarthrosis or haematoma as a complication.     

Acute lateral patellar dislocation at MR imaging: injury patterns of medial patellar soft-tissue restraints and osteochondral injuries of the inferomedial patella

PURPOSE: To assess magnetic resonance (MR) imaging findings after acute lateral patellar dislocation (LPD) with emphasis on the medial patella restraints and to describe a medial patellar impaction deformity. MATERIALS AND METHODS: Knee MR images obtained within 8 weeks after LPD were evaluated for medial retinacular and medial patellofemoral ligament (MPFL) disruption, vastus medialis obliquus (VMO) edema and/or elevation, and other derangements. One hundred patients with no evidence of prior LPD were evaluated as controls. The Student t test was used for statistical comparisons. RESULTS: Eighty-two examinations were performed in 81 patients with LPD (mean age, 20 years; age range, 9-57 years). Seventy-six percent (62 of 82 examinations) showed medial retinacular disruption at its patellar insertion; 30% (25 of 82), at its midsubstance. The MPFL femoral origin was identified in 87% (71 of 82); of these, 49% (35 of 71) showed injury. Forty-eight percent (39 of 82) showed more than one site of injury to the medial stabilizers; 45% (37 of 82) showed edema or hemorrhage at the inferior VMO. Mean VMO elevation in the coronal plane of the adductor tendon was 2.2 cm, with a range of 0.6-4.5 cm (in control subjects, 0.9 cm; range, 0.1-2.5 cm; P <.001). At the inferomedial patella, 70% (57 of 82) of LPD examinations showed osteochondral injury and 44% (36 of 82) showed concave impaction deformity (0 of 100 control subjects). Other examination findings in LPDs included contusions of the lateral femoral condyle (66 [80%] of 82 examinations) or medial patella (50 [61%] of 82), intraarticular bodies (12 [15%] of 82), effusion (45 [55%] of 82), medial collateral injury (nine [11%] of 82), and meniscal tear (nine [11%] of 82). CONCLUSION: Injury to the medial retinaculum, MPFL, and VMO may be identified at MR imaging after acute LPD. Concave impaction deformity of the inferomedial patella is a specific sign of prior LPD.     

Patellar tendon length after anterior cruciate ligament reconstruction: a comparative magnetic resonance imaging study between patellar and hamstring tendon autografts

Patellar tendon shortening after anterior cruciate ligament reconstruction may be associated with anterior knee pain or patellofemoral arthritis. The present study was designed to compare postoperative changes in patellar tendon length after anterior cruciate ligament reconstruction between patellar tendon and hamstring tendon autograft. Magnetic resonance images of both knees (operated and healthy) and functional outcome were documented at least 1 year postoperatively in 16 patellar tendon harvested patients and in 32 hamstrings harvested patients. Patellar tendon length, patella length and Insall–Salvati ratio were measured. The operated knee values were compared to the respective values of the non-operated control knees. A significant 4.2 mm or 9.7% patellar tendon shortening in patellar tendon group and a non-significant 1.14 mm or 2.6% shortening in hamstrings group was detected. No significant difference was detected in terms of major shortening—patella baja—(6% for the patellar tendon group vs. 0% for the hamsting group). There was no significant difference in anterior knee problems between the two groups as evidenced by the Shelbourne score (94 for the patellar tendon group vs. 98 for the hamsting group). Harvesting of the patellar tendon for anterior cruciate ligament reconstruction resulted in a significant shortening of the remaining tendon. In contrast harvesting of the hamstring tendons did not affect significantly the patellar tendon length. However, the incidence of patella baja and overall functional outcome was not significantly different between the two groups. Paper presented at the 12th ESSKA 2000 Congress, Innsbruck, Austria, 2006 and also presented at the 5th Biennial ISAKOS Congress, Hollywood, FL, USA, 2005.     

Patellar tendon shortening after treatment of patellar instability with a patellar tendon medialization procedure

Patellar instability is a multifactorial disorder. Patella alta is strongly associated with patellar instability. We hypothesize that procedures of the patellar tendon such as medialization may shorten the patellar tendon. In this retrospective study, 41 patients with patellar instability were treated operatively with a patellar tendon medialization procedure. Twenty-eight knees were treated using a modified Roux–Goldthwait method and 16 using a modified Elmslie–Trillat method. The patients were followed 2–7 years after the operation. Pre- and post-operative x-rays were analyzed with particular emphasis on patellar tendon length, patellofemoral congruence angle and osteoarthritis. The final clinical outcome was assessed using the Lysholm score and clinical examination. In both groups patients were generally satisfied with the result of the operation and there was no significant difference in Lysholm scores at follow-up. However, patellofemoral osteoarthritic changes increased in both groups compared with the pre-operative status. The patellar tendon length was reduced in both groups, but significantly, by 7%, in the Roux–Goldthwait group. We conclude that patellar tendon shortens after a Roux–Goldthwait procedure.     

急性髌骨外侧脱位患者性别、年龄、解剖参数与髌股关节软骨损伤的相关性

目的 探讨急性髌骨外侧脱位(lateral patellar dislocation,LPD)患者性别、年龄、髌股关节解剖参数与髌股关节软骨损伤的相关性.方法 回顾性分析2015-01至2021-07在武警山东总队医院就诊的115例经临床证实为急性LPD患者的MRI资料,对患者性别、年龄[分为青少年(<18岁)、成人(...     

Long patellar tendon: radiographic sign of patellofemoral pain syndrome--a prospective study.

The position of the patella was studied prospectively in both knees of 45 consecutive patients (21 male and 24 female patients aged 16-48 years who were competitive [n = 17] or recreational [n = 28] athletes) who had unilateral patellofemoral pain syndrome without symptoms or signs of patellar instability at initial examination. In each knee, standardized anteroposterior, lateral, and tangential radiographs were obtained and six indexes of patellar position (the ratio of the patellar tendon to the greatest diagonal length of the patella, sulcus angles, lateral patellofemoral angle, lateral patellar displacement, patellofemoral index, and knee angle) were measured. When healthy and affected knees were compared, high riding of the patella due to long patellar tendon (patella alta) was the only definite finding in the affected knees. The shape of the intercondylar sulcus and the mediolateral position of the patella were identical in both knees, providing no evidence for patellofemoral incongruence or lateral patellar tilt. Results of this study strongly suggest that idiopathic retropatellar pain is closely associated with patella alta.     

Prevalence of cartilage lesions and early osteoarthritis in patients with patellar dislocation

Objectives

Assessment of cartilage lesions and osteoarthritis (OA) of the patellofemoral joint in patients following lateral patellar dislocation using magnetic resonance imaging (MRI).

Methods

MR images of 129 knees (mean age 26?years, range 11–56) grouped as acute (A), recurrent (B), and chronic (C) dislocators were analysed regarding the prevalence and severity of patellofemoral cartilage lesions. Grades of OA were assessed using modified WORMS.

Results

In groups A, B, and C the prevalence of cartilage lesions was 71%, 82%, and 97%, respectively. Most lesions were located on the central patella in groups A and B (central 69% and 78%; medial 56% and 47%; lateral 31% and 42%), whereas group C revealed all regions affected (73%, 61%, and 67%). Of group A, 14% had mild OA and 64% of group B. Group C showed mild OA in 62% and moderate OA in 18%. Cartilage defect size and prevalence of OA was correlated with number of dislocations (r?=?0.41 and r?=?0.59; P?<?0.001).

Conclusions

Cartilage lesions and early OA are common after patellar dislocation and appear to increase with the frequency of dislocation. Both conditions should be considered when interpreting MRI in such patients, because of implications for treatment.

Key Points

? Cartilage lesions are very common after patellar dislocation. ? The severity of cartilage lesions increases with number of dislocations. ? Osteoarthritis is common after recurrent patellar dislocation, even in young patients. ? Detecting cartilage lesions is important after patellar dislocation.     

The association of infrapatellar fat pad oedema with patellar maltracking: a case–control study

Objective

To look for any association between oedema in the superolateral portion of the infrapatellar fat pad and patellar maltracking.

Materials and methods

We compared two groups of knee MRI with regard to five patellar maltracking parameters. The first group included 100 knees with evidence of oedema in the superolateral aspect of the infrapatellar fat pad (the study group). The second group included another 100 knee MRI that had a normal infrapatellar fat pad (the control group). The five patellar maltracking parameters assessed were the trochlear depth, tibial tuberosity–trochlear groove distance (TTTG), patellar translation, patellofemoral angle (PFA) and the Insall–Salvati index.

Results

There was a statistically significant difference in the Insall–Salvati index, patellar translation and PFA between the two groups (p value of <0.001, <0.001 and 0.004 respectively, Student’s t test). There was a higher prevalence of patella alta, lateral patellar displacement (LPD) and lateral patellar tilt in the study group (p value of <0.001, <0.001 and 0.011 respectively, Fisher’s exact test). Sixty out of 100 knees in the study group had at least one abnormal patellar maltracking parameter in comparison to 16 out of 100 knees in the control group (p?Conclusion Oedema in the superolateral portion of Hoffa’s fat pad, the MRI feature of fat pad impingement, is associated with patellar maltracking.     

Incidence and radiologic predictor of postoperative patellar instability after Fulkerson procedure of the tibial tuberosity for recurrent patellar dislocation

Purpose

Excellent results of anteromedialization of the tibial tuberosity for recurrent patellar dislocation have been reported; however, the contribution of the preoperative anatomic factors to postoperative patellar instability has not been well established. The purpose of this study was to investigate the mid-term results and the incidence of postoperative patellar instability after Fulkerson procedure for recurrent patella dislocation, and to determine the radiologic predictor of the postoperative patellar instability.

Methods

Sixty-two knees of 41 patients underwent Fulkerson procedure with or without lateral retinacular release for recurrent patellar dislocation and were followed-up for 85–155 months. Predisposing anatomic factors for recurrent patellar dislocation were evaluated preoperatively, including valgus knee alignment (femorotibial angle), patella alta (Insall–Salvati ratio), trochlear dysplasia (trochlear depth), lateral patellar displacement (congruence angle) and lateral malposition of the tibial tuberosity (tibial tuberosity-trochlear groove distance). The relationship between the measurements of anatomic factors and postoperative patellar instability, which was defined by the patellar re-dislocation or residual apprehension after surgery, was analyzed.

Results

The Fulkerson score and the Kujala score were significantly improved from the median of 65 (35–80) points and 68 (36–82) points preoperatively to 95 (60–100) points and 92 (57–100) points at the final follow-up, respectively. Three knees (4.8%) experienced postoperative patellar re-dislocation and 4 knees (6.5%) showed the positive apprehension sign at the final follow-up. The statistical analysis showed that the postoperative patellar instability correlated with only patella alta.

Conclusion

Patella alta was the only predictor of postoperative patellar instability after Fulkerson procedure. These results indicated that isolated Fulkerson procedure should not be indicated for recurrent patellar dislocation with severe patella alta.

Level of evidence

Case–control study, Level III.     

Lateral retinaculum plasty instead of lateral retinacular release with concomitant medial patellofemoral ligament reconstruction can achieve better results for patellar dislocation

Purpose

To elucidate the outcomes of lateral retinaculum plasty versus lateral retinacular release with concomitant medial patellofemoral ligament (MPFL) reconstruction.

Methods

In a prospective study, 59 patients treated at our institution from 2012 to 2014 were included. The 59 patients were randomly divided into two groups. Group I included 27 patients who underwent lateral retinacular release and MPFL reconstruction. Group II included 32 patients who underwent lateral retinaculum plasty and MPFL reconstruction. All patients were followed up for at least 2 years and all assessments were performed both pre- and post-operation. Clinical evaluation consisted of the Kujala score, patellar medial glide test, and patellar tilt angle, patellar lateral shift, and congruence angle, measured on CT scan.

Results

Significant improvement was seen after surgery in both groups. The group of lateral retinaculum plasty achieved better results than the group of lateral retinacular release. No statistically significant differences were found in lateral patellar shift (ns) or congruence angle (ns) between the groups. There were significant differences in Kujala score (P?<?0.05) patellar tilt angle (P?<?0.05), and patellar medial glide test (P?<?0.05) between the groups.

Conclusions

MPFL reconstruction with lateral retinaculum plasty yielded better results than MPFL with lateral retinacular release. Postoperatively, medial and lateral function were restored, and patellar tracking was normal. Lateral retinaculum plasty is a new method that reduces the complications of lateral retinacular release for patellar dislocation.

Level of evidence

II.

     

Medial patellofemoral ligament reconstruction in patients with lateral patellar instability and trochlear dysplasia

BACKGROUND: Reconstruction of the medial patellofemoral ligament has been proven to restore stability in patients with lateral patellar instability. No study to date has examined the results in a patient population with the predisposing factor of femoral trochlear dysplasia. HYPOTHESIS: Reconstruction of the medial patellofemoral ligament restores stability and provides pain relief in patients who have lateral patellar instability in association with trochlear dysplasia. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Thirty-four patients with chronic patellar instability and trochlear dysplasia were treated with medial patellofemoral ligament reconstruction using an adductor tendon autograft, bone-quadriceps tendon autograft, or bone-patellar tendon allograft. All patients were evaluated preoperatively and postoperatively with Kujala, Lysholm, and Tegner scores at a minimum of 24 months. RESULTS: Thirty-four patients were followed for a mean of 66.5 months (range, 24-130 months) after surgery. Kujala scores improved from 53.3 to 90.7, Lysholm scores improved from 52.4 to 92.1, and Tegner activity scores improved from 3.1 to 5.1. All improvements were highly statistically significant (P < .001). No statistical difference was found between the postoperative Lysholm, Kujala, and Tegner scores and the degree of dysplasia, graft type, or degree of symptoms. There were 85.3% and 91.1% good and excellent results based on Kujala and Lysholm scores, respectively. No recurrent dislocations have occurred. CONCLUSION: Medial patellofemoral ligament reconstruction provides excellent long-term pain relief and functional return in patients with patellar instability and femoral trochlear dysplasia. In addition, reconstruction prevents recurrent dislocation, despite the diminished bony constraint of a dysplastic trochlea.     

The influence of the lower patellar pole in the pathogenesis of chronic patellar tendinopathy

Resection of the lower patellar pole provides good results in the treatment of jumper’s knee. Therefore we hypothesized that the length of the lower patellar pole is increased in patients with chronic patellar tendinopathy. Cohort study, level of evidence 2. Between 2000 and 2005, 25 patients with chronic patellar tendinopathy underwent conservative and surgical treatment in our clinic. All of them had preoperative MRI were three independent examiners measured the Caton Index, the length and the ratio of the articular and non-articular patellar surface, tendon length and thickness and the thickness and length of the hypodens lesions in the patellar tendon. The measurements were compared with 50 MRI of a control group with no clinical patellofemoral disorders or patellar tendinopathy. Significant changes in tendon thickness (9.42 ± 2.87 vs. 4.88 ± 1.13; P < 0.0001), a longer non-articular surface of the patella (10.62 ± 2.86 vs. 7.098 ± 2.53; P < 0.0001) and significant higher ratio between the articular and the non-articular patellar surface (0.32 vs. 0.24; P < 0.0001) were found in the jumper’s knee group. No significant changes were seen in the length of the articular surface or the Caton Index. The development of chronic patellar tendinopathy in athletes might be associated with a longer lower patellar pole as patients with jumper’s knee showed a longer non-articular patellar surface compared with the control group.     

Objective patellar instability: MR-based quantitative assessment of potentially associated anatomical features

To evaluate and compare the diagnostic utility of multiple quantitative parameters as measured on knee magnetic resonance (MR) examinations of patients suffering objective patellar instability (OPI). We performed a retrospective evaluation of knee MR examinations in a group of 46 patients (59 knees) with clinically proven OPI, and in a control group of 69 patients (71 knees). Multiple quantitative parameters in both groups were statistically evaluated and compared for their association with OPI. OPI patients tend to present shallower trochlear groove (<5 mm), larger Insall-Salvati index (>1.2), shorter patellar nose (<9 mm), smaller morphology ratio (<1.2), and larger patellar tilt (>11°) than control patients. The best sensitivities were those of the lateral patellar tilt (92.7%), the trochlear groove depth at the roman arch level (85.7%) and the Insall-Salvati index (78%). The best specificities were those of the morphology ratio (86.9%), the patellar nose (84.5%) and the patellar tendon length (84.5%). Shallow trochlear groove may be confidently identified at the roman arch view in OPI patients. Patella alta may be more reliably detected by the Insall-Salvati index in OPI patients. Patellar nose and morphology ratio are very specific indicators of OPI. A short patellar nose (that is to say, a patellar nose ratio of <0.25) has a high association with OPI. Lateral patellar tilt remains the single feature with the highest sensitivity and specificity for identifying OPI patients.The investigation was performed at: Hospital Universitari de Tarragona Joan XXIII, Tarragona, Spain, and Hôpital de la Croix-Rousse, Centre Livet, Caluire, FrancePresented as a scientific paper (731) at the RSNA 2003, original research     

Healing of the patellar tendon after harvesting of its mid-third for anterior cruciate ligament reconstruction and evolution of the unclosed donor site defect

The purpose of this study was (a) to evaluate by ultrasonography the healing of the patellar tendon after its mid-third was removed for anterior cruciate ligament (ACL) reconstruction in two randomized groups of patients in whom the tendon donor site was either left open or closed: (b) to compare clinical, radiographic, and isokinetic studies of these two groups to evaluate the incidence of patellofemoral disorders. We performed 61 ACL reconstructions (22 males, 39 females) using the arthroscopically assisted in-out technique. All operations were performed by the same surgeon, and the patients were all subjected to the same postoperative protocol. The tendon defect was left open in 25 subjects (group A) and was closed in 36 subjects (group B). Postoperative patellar tendon behavior was evaluated in these two groups by ultrasonography at 3, 6, 9, and 12 months. The vertical position of the patella was measured in the follow-up lateral view at 45° of flexion and compared to that of the untreated knee. A clinical evaluation was performed throughout the follow-up period. and patellofemoral problems (pain, stiffness, patellofemoral crepitus) were evaluated and recorded using a modified Larsen and Lauridsen rating scale. Isokinetic evaluation was carried out at 6 months, and a quadriceps index of the two groups was recorded. Ultrasonography showed that healing of the patellar tendon initially progressed with a compensatory hypertrophy in width and thickness. The width was greater in group B (P<0.01). In group A we observed in the cross-sections a characteristic image of two cords separated by a low signal bridge which we defined as a binocular pattern. Areas of high ultrasound signal intensities persisted after 1 year in the open group: such areas were filled with scar tissue. In the closed group the ultrasound tendon signal returned to normal at 1 year. At 6 months the clinical, radiographic and isokinetic findings did not significantly differ between the open and closed groups. We conclude that defect closure after patellar tendon harvesting does not significantly influence the extensor apparatus.     

A 6-year follow-up of the effect of graft site on strength, stability, range of motion, function, and joint degeneration after anterior cruciate ligament reconstruction: patellar tendon versus semitendinosus and Gracilis tendon graft

BACKGROUND: The choice of graft material for anterior cruciate ligament reconstruction remains controversial. Despite the need for well-controlled, long-term outcome studies comparing patellar tendon with hamstring grafting, few studies have followed results for more than 5 years. HYPOTHESIS: Graft source will not affect outcome 6 years after reconstruction. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Sixty-two patients with anterior cruciate ligament reconstruction and 18 uninjured control subjects were studied over 6 years. Thirty-one patients received patellar tendon grafts, and 31 received hamstring tendon grafts. Assessment included knee joint stability, range of motion, muscle strength, subjective function, objective function (running, sidestepping, carioca, and hop tests), and joint degeneration. RESULTS: Clinical stability was restored to all patients other than to the 2 hamstring graft recipients who suffered reinjuries. The KT-1000 arthrometer side-to-side differences were similar in the patellar tendon (1.9 mm) and hamstring tendon (2.0 mm) groups but were significantly greater than that of uninjured control subjects (P < .001). There were no significant strength differences between surgical and control groups, although a 6% quadriceps deficit existed after patellar tendon grafting. In the more demanding functional tests (hop and triple-hop indices and carioca), the hamstring graft recipients performed similarly to the control group, whereas a significant difference (P < .05) existed between the patellar tendon graft and the control group. The incidence of early tibiofemoral osteoarthritis was significantly greater after reconstruction using patellar tendon (62%) than after hamstring tendon grafting (33%; P = .002). CONCLUSION: Six-year outcomes were very satisfactory irrespective of graft source. However, reconstruction using the hamstring tendons resulted in improved functional performance and a lower incidence of osteoarthritis.