Combined medial and lateral patellar retinaculum plasty for skeletally immature patients with patellar dislocation and low-grade trochlear dysplasia

BackgroundTo evaluate the clinical outcomes of combined medial and lateral patellar retinaculum plasty for skeletally immature patients with patellar dislocation and low-grade trochlear dysplasia.MethodsFrom December 2014 to December 2016, we reviewed 19 skeletally immature patients who underwent medial and lateral patellar retinaculum plasty at our institution. Clinical evaluations were performed pre- and postoperatively, and included determination of the number of patellar re-dislocation patients, the Kujala and Tegner scores, the patellar tilt angle, lateral patellar shift, and congruence angle. The radiographic evaluation parameters were measured on computed tomography scans.ResultsNo dislocation or subluxation occurred during the mean follow-up of 35.42 months (24–48 months). Postoperatively, the Kujala score improved from 57.6 ± 4.2 to 86.9 ± 8.1 (P < 0.05), and the Tegner activity score improved from 2.6 ± 1.0 to 5.0 ± 1.3 (P < 0.05). Radiographically, the patellar tilt angle decreased from 32.7 ± 5.9° to 13.4 ± 4.28° (P < 0.05), the lateral patellar shift decreased from 15.9 ± 1.1 mm to 8.4 ± 0.6 mm (P < 0.05), and the congruence angle decreased from 29.9 ± 15.3° to − 9.6 ± 15.5° (P < 0.05).ConclusionsMedial and lateral patellar retinaculum plasty is a promising procedure that has the advantage of being a simple operation that induces little trauma. It is a good treatment option for skeletally immature patients with patellar dislocation who have low-grade trochlear dysplasia.     

Recurrent patellar dislocations with patellar cartilage defects: A pain in the knee?

BackgroundRecurrent patellar dislocation in combination with cartilage injures are difficult injuries to treat with confounding pathways of treatment. The aim of this study was to compare the clinical and functional outcomes of patients operated for patellofemoral instability with and without cartilage defects.MethodsEighty-two patients (mean age 28.8 years) with recurrent patellar dislocations, who underwent soft-tissue or bony procedures, were divided into two matched groups (age, sex, follow up and type of procedure) of 41 each, based on the presence or absence of cartilage defects in patella. Chondroplasty, microfracture, osteochondral fixation or autologous matrix-induced chondrogenesis (AMIC)-type procedures were performed depending on the nature of cartilage injury. Lysholm, Kujala, Tegner and Subjective Knee scores of both groups were compared and analysed. Complications and return to surgery were noted.ResultsWith a mean follow up of 8 years, there was a significant improvement observed in all the mean postoperative patient-reported outcome measures of both groups, as compared with the preoperative scores (P < 0.05). Comparing the two groups, postoperative Lysholm, Kujala and Subjective knee scores were significantly higher in patients operated without cartilage defects (P < 0.05). Three patients operated for patellofemoral instability with cartilage defects underwent patellofemoral replacement subsequently. The odds ratio for developing complications was 2.53 for patients operated with cartilage defects.ConclusionAlthough there is a significant improvement in the long-term outcome scores of patients operated for recurrent patellar dislocation with cartilage defects, the results are significantly inferior compared with those without cartilage defects, along with a higher risk of developing complications and returning to surgery.     

Combined deepening trochleoplasty and supracondylar external rotation osteotomy for recurrent patellar instability in patients with trochlear dysplasia and increased femoral antetorsion

BackgroundDeepening trochleoplasty has become a part of surgical management in patients with patellar instability and severe trochlear dysplasia. In addition, increased femoral antetorsion is treated most commonly by proximal femoral external rotation osteotomy.HypothesisDeepening trochleoplasty and supracondylar femoral external rotation osteotomy in combination improve patellar stability and function in patients presenting with recurrent patellar instability due to trochlear dysplasia and increased femoral antetorsion.Study designTherapeutic case series; Level IV.MethodsCombined deepening trochleoplasty and supracondylar external rotation osteotomy were performed in seven female patients (nine knees) with recurrent patellar instability. Trochlear dysplasia (Dejour classification) and increased femoral antetorsion (Murphy computed tomography (CT)-based measurement) were documented using magnetic resonance imaging and CT scans. Data were collected prospectively preoperatively, at 12 months, and at final follow-up. Complete data were available in 100% of cases. Clinical and functional outcomes were evaluated using the Kujala score and Tegner activity level scale.ResultsThe average age at the time of surgery was 22.2 years (range, 17–29 years). Preoperative MRI-based findings demonstrated in all patients significant trochlear dysplasia (B in two, C in five, and D in two knees). Femoral antetorsion was 37.8° on average (range, 27–51°). The mean follow-up was 2.1 years after surgery (range, 1–5.5 years). The median Kujala score was 41.2 preoperatively, rising to 83.1 at final follow-up (P = .015). The Tegner activity score improved from a mean preoperative score of 2.7 to a mean postoperative score of 6.0 (P = .020). Good patellar stability without positive apprehension sign was found in all patients. Poor outcome was associated with significant patellofemoral cartilage damage (grade IV) at the time of surgery. A total of 88.8% of patients were satisfied with the knee function at final follow-up. There were no postoperative complications.ConclusionThe combination of deepening trochleoplasty and supracondylar external rotation osteotomy performed in one step is an individually adapted surgical procedure for restoring both horizontal limb alignment and trochlear geometry. It improves patellar stability and yields good subjective and objective functional results in most cases. The condition of the cartilage at the time of surgery is crucial for the outcome with respect to the pain.     

Treatment of osteochondritis dissecans of the patella in adolescents with nanofractured autologous matrix-induced chondrogenesis (NAMIC): A report of five cases

PurposeOsteochondritis dissecans (OCD) of the patella is a very rare affliction. The aim of this case series is to evaluate the effectiveness of the Nanofractured Autologous Matrix-Induced Chondrogenesis (NAMIC) technique for the treatment of OCD in young adults.MethodsFive consecutive patients with patellar osteochondral lesions treated with NAMIC were prospectively studied. There were 4 males and 1 female with a mean age of 15.2 years, ranging from 12 to 18 years. Clinically, they presented pain when going up and down stairs or squatting, effusion, swelling and functional limitation. The International Cartilage Repair Society (ICRS) grade was III in 4 patients and IV in 1 patient. Patients were functionally evaluated with the Lysholm knee score, the Tegner Activity Score (TAS) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) and radiologically using the Magnetic resonance Observation of Cartilage Repair Tissue (MOCART) score.ResultsAll the scores significantly improved two years after surgery with respect to pre-operative values (Lysholm score from 63.8 ± 3.9 before surgery to 91 ± 3.2 at 2 years; Tegner activity score from 3.6 ± 0.5 to 8.2 ± 0.8 and the KOOS score from 45.2 ± 2.6 to 91.2 ± 2.4). Both the X-rays and the Magnetic Resonance Imaging (MRI) showed good joint regularity with an average MOCART of 80 ± 7.1/100.ConclusionsTreatment of juvenile patellar osteochondritis dissecans with the NAMIC technique seems to be a reliable technique in the short term to restore the patella joint surface and obtain good functional results.     

Long-term clinical and radiological outcomes after multiligament knee injury using a delayed ligament reconstruction approach: A single-center experience

PurposeTo present long-term clinical and radiological results of patients treated with delayed reconstruction of multiligament knee injuries.MethodsClinical data from 26 patients (21 men, five women, mean age 27.44 years) were retrospectively reviewed. Patients were evaluated at final follow-up with the use of: The International Knee Documentation Committee score (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), Tegner Activity level, Lysholm Knee Scoring Scale, EuroQol subjective knee evaluation form, and KT-2000 arthrometer. Mean follow-up time was 105.38 months. Both knees were radiographically evaluated for osteoarthritis according to the Kellgren–Lawrence classification.ResultsNo patient required mobilization under anesthesia for adhesion lysis at the immediate or later postoperative duration. There was no statistically significant difference in range of motion between the healthy and operated sides (P = 0.713). Mean time to final range of motion regain was 2.1 ± 0.4 months. Average KT-2000 side-to-side (operated vs. normal) difference was 2.03 ± 1.1 mm, and the difference was statistically significant (P = 0.007). The mean IKDC, KOOS, Lysholm, Tegner, and Euroqol-5D postoperative scores were 82.13 ± 17.5, 84.59 ± 16.8, 90.6 ± 6.4, 4.3 ± 1.3, and 80 ± 11.74, respectively. Multiple regression analysis showed that age and follow-up time had significant effects on each clinical score, except for the Lysholm and Tegner scores. Progression of osteoarthritic changes of the reconstructed knee and its contralateral side was significantly different (P = 0.003).ConclusionExcellent clinical results were reported from this center's long-term experience with delayed ligament reconstruction, and osteoarthritic changes of reconstructed knees were recorded.     

All-inside repair of bucket handle meniscus tears – Mid-term outcomes with postoperative magnetic resonance imaging

PurposeThe purpose of this study was to evaluate our results of bucket handle meniscus tear (BHMT) repairs with an all-inside repair technique using postoperative radiological imaging to evaluate meniscus reduction and healing and use them as criteria for evaluation of repair success.MethodsProspective recruitment of 20 patients with 21 BHMT repairs performed with an all-inside technique over a period from 2013 to 2015. All patients had an International Knee Documentation Committee (IKDC) Subjective Knee Form (SKF), Lysholm Score, Knee Injury and Osteoarthritis Outcome Score (KOOS) and Tegner Activity Level Scale obtained pre-operatively and at a minimum of 24 months after surgery. All patients had postoperative knee magnetic resonance imaging (MRI) performed between 18 and 24 months after surgery to assess the stability or failure of their repairs. At 5 years after surgery, the patients were assessed with regard to whether they had undergone repeat surgery or not.ResultsAt 2 years, the mean postoperative SKF, Lysholm and KOOS grand scores were 78.9, 88.5 and 86.8, respectively. The mean pre-injury Tegner Activity Scale was 7.6 and postoperatively it was 6.0. There was a significant difference in all pre- and postoperative outcome scores (P < 0.01).The postoperative MRIs showed that 19 of the 21 BHMT repairs had stable reduction of the tear fragment and two patients had displacement of the torn bucket handle fragment. At 5 years, one patient had undergone revision surgery.ConclusionBHMTs can be repaired with all-inside techniques with good results and successful outcomes.     

Clinical outcomes of medial patellofemoral ligament reconstruction using FiberTape and knotless SwiveLock anchors

BackgroundWe aimed to prospectively investigate the clinical outcomes of medial patellofemoral ligament (MPFL) reconstruction using polyester high-strength suture tape with knotless anchors.MethodForty-three patients (65 knees) were followed for at least 1 year postoperatively, with 27 patients (43 knees) followed for 2 years postoperatively. All patients underwent MPFL reconstruction using polyester high-strength suture tape (FiberTape®; Arthrex) with knotless anchors (SwiveLock®; Arthrex). Repeated dislocation and residual patellar apprehension signs were recorded, and congruence and tilting angles were measured. Changes in Knee Injury and Osteoarthritis Outcome Scale (KOOS) scores and their associations with the preoperative tibial tubercle–trochlear groove (TT-TG) distance were analyzed.ResultsNo repeat dislocations (0%) were observed. One (2.4%) residual positive patellar apprehension sign was noted. The mean tilting angle decreased from 24.8° to 10.7° (P < 0.001), and the mean congruence angle decreased from 24.9° to 4.3° (P < 0.001). At 2 years follow up, all KOOS subscales had improved: pain (92.0 ± 12.9), symptoms (90.2 ± 11.9), activities of daily living (95.7 ± 7.3), sports activity (85.7 ± 16.9), quality of life (87.7 ± 12.9), and patellofemoral (89.0 ± 9.6) outcomes. KOOS subscale scores improved regardless of the preoperative TT-TG distance (21.1 ± 3.5 mm; range, 13.8–29.9 mm).ConclusionsMPFL reconstruction using FiberTape and knotless SwiveLock anchors was performed without sacrificing autologous tissue. No recurrent patellar dislocation was observed during the 2-year follow up period. All KOOS subscale scores improved using FiberTape and SwiveLock anchors in MPFL reconstruction.     

Infrapatellar fat pad-derived mesenchymal stem cell therapy for knee osteoarthritis

PurposeThe aim of the study was to determine if isolated mesenchymal stem cells (MSCs) derived from the infrapatellar fat pad could effectively improve clinical results when percutaneously injected into arthritic knees.Level of evidenceTherapeutic case–control study; Level III.MethodsTwenty five stem cell injections combined with arthroscopic debridement were administered to patients with knee OA. A mean of 1.89 × 10⁶ stem cells were prepared with approximately 3.0 mL of platelet-rich plasma (PRP) and injected in the selected knees of patients in the study group.ResultsThe mean Lysholm, Tegner activity scale, and VAS scores of patients in the study group improved significantly by the last follow-up visit. No major adverse events related to the injections were observed during the treatment and follow-up periods. The results were compared between the study and control groups, in which the patients had undergone arthroscopic debridement and PRP injection without stem cells. Although the preoperative mean Lysholm, Tegner activity scale, and VAS scores of the study group were significantly poorer than those of the control group, the clinical results at the last follow-up visit were similar and not significantly different between the two groups.ConclusionsThe short-term results of our study are encouraging and demonstrate that infrapatellar fat pad-derived MSC therapy with intraarticular injections is safe, and provides assistance in reducing pain and improving function in patients with knee OA.     

Patellar tendon lengthening and augmentation with quadriceps tendon graft for treatment of severe patella infera

BackgroundPatella infera represents a permanent abnormally low position of the patella with three characteristics: distal position of the patella in the femoral trochlea, permanent shortening of the patellar tendon, and decreased distance between the inferior pole of the patella and the articular surface of the tibia. Several surgical techniques have been described to resolve this disabling condition with varying outcomes.HypothesisLengthening of the shortened patellar tendon with augmentation using a quadriceps tendon graft in combination with excessive intra-articular release improve knee function in patients presenting with severe and permanent patella infera.MethodsNine patients (four males, five females) with significant patella infera were treated between 2004 and 2020. The low position of the patella was documented using the Caton–Deschamps index. The Tegner Lysholm knee scoring scale and the Numerical Rating Scale (NRS) for pain were used as outcome measures before surgery and at follow up. Complete data were available in 100% of cases at 12 months follow up, and in 78% at final follow up.ResultsThe average follow up was 4.2 years (range, 1–16 years). The Tegner Lysholm score improved from a mean preoperative score of 43.8 to a mean postoperative score of 80.5. The median NRS status decreased from an average of 6.7 (range, 5–8) to 2.3 (range, 1–7). The median preoperative flexion was 103.3° (range, 40–125°), rising to 126.6° (range, 40–145°). The median preoperative Caton–Deschamps ratio of 0.32 (range, 0–0.6) improved to 0.99 (range, 0.9–1.1) at final follow up. Two patients needed additional surgical treatment (arthroscopic scar tissue removal and proximalisation of the tibial tuberosity).ConclusionLengthening of a shortened patellar tendon with augmentation using a quadriceps tendon graft combined with excessive intra-articular release is an individually adapted surgical salvage procedure to treat permanent patella infera. It improves knee function and yields good to excellent results in most cases.     

Osteochondral autologous graft transfer system in the knee; mid-term results

IntroductionThe purpose of this study was to determine the effectiveness of the osteochondral autologous graft transfer system in the treatment of chondral and osteochondral lesions of the knee.MethodsSixty five knees of sixty four patients who underwent autologous osteochondral graft transfer were evaluated with clinical scores and imaging techniques.ResultsThe average follow up was 82.2 (51–145) months. The patients were evaluated according to Tegner activity scale, Lysholm scale and IKDC subjective knee evaluation form. According to all these scales, all patients showed increasing results in various rates in the last follow up. Accordingly, mean increases of 59.2 ± 15.9 points, 3.6 ± 1.4 points, and 42.6 ± 11.5 points were achieved in Lysholm knee scores, Tegner activity scale scores, and IKDC subjective knee evaluation form, respectively (p ≤ .0001). Moreover, we found no significant correlation between functional results and age, functional results and localization of osteochondral defect, functional results and additional knee pathologies.ConclusionIn our study we achieved significant increases in all the scales in the last follow up. Furthermore, we found no significant correlation between functional results and age, defect localization and additional knee pathologies.     

MPFL reconstruction using a quadriceps tendon graft: Part 2: Operative technique and short term clinical results

BackgroundWe describe the preliminary clinical results of a new operative technique for MPFL reconstruction using a strip of quadriceps tendon (QT).MethodsPatients: 17 patients (7 male, 10 female; mean age 21.5 years ± 3.9) have been operated on with this technique. All patients were evaluated clinically, radiologically and with subjective questionnaires (Tegner-, Lysholm-, Kujala Score) pre-operatively and post-operatively at 6 and 12 months (m).Surgical technique: A 10 to 12 mm wide, 3 mm thick and 8 to 10 cm long strip from the central aspect of quadriceps tendon is harvested subcutaneously. The tendon strip is then dissected distally on the patella, left attached, diverged 90° medially underneath the medial prepatellar tissue and fixed with 2 sutures. The graft is fixed in 20° of knee flexion with a bioabsorbable interference screw.ResultsLysholm score at 6 m was 81.9 ± 11.7 and at 12 m 88.1 ± 10.9, Kujala score at 12 m was 89.2 ± 7.1 and Tegner Score was 4.9 ± 2.0 (6 m) and 5.0 ± 1.9 (12 m). Two patients had a positive apprehension test at 12 months. There was no re-dislocation during the follow-up period.ConclusionMPFL reconstruction with a strip of QT harvested in a minimal invasive technique was found to be associated with good short term clinical results. We think that this technique presents a valuable alternative to common hamstring techniques for primary MPFL reconstruction in children and adults, as well as for MPFL revision surgery.Level of evidenceIV, prospective case series.     

自体半腱肌肌腱双束重建内侧髌股韧带治疗不伴有骨性畸形的复发性髌骨脱位

目的 探讨自体半腱肌肌腱双束重建内侧髌股韧带(MPFL)治疗不伴有骨性畸形的复发性髌骨脱位的临床疗效。方法 回顾性分析2015年6月—2017年12月芜湖市中医院采用自体半腱肌肌腱双束解剖重建MPFL的12例不伴有骨性畸形的复发性髌骨脱位患者的临床资料,其中男2例、女10例,年龄14～46(27.75±10.14)岁。所有患者术中髌骨侧采用2枚带线锚钉固定移植物,关节镜下调节张力后股骨侧采用界面挤压螺钉固定移植物。术后定期进行随访,主观评价髌股关节摩擦感、髌骨异常活动、髌骨外推试验及外推恐惧试验、膝关节活动度、肌力检测,影像学(X线片及CT)评估测量骨道位置,采用Lysholm、Tegner和Kujala主观评分评价手术前后膝关节功能。结果 12例患者手术均顺利,术后随访12～24个月,平均13.5个月。术后均无髌骨再脱位、髌骨错动,0°位和屈膝30°位髌骨外推试验和外推恐惧试验均为阴性。Lysholm评分术前为(66.00±4.71)分、末次随访为(92.67±3.23)分,Tegner评分术前为(3.33±0.89)分、末次随访为(5.33±0.78)分,Kujala主观评分术前为(53.67±3.23)分、末次随访为(91.50±2.68)分,差异均有统计学意义(t=16.248、32.176、89.350, P值均＜0.01)。结论 对于不伴有骨性畸形的复发性髌骨脱位的患者,自体半腱肌肌腱双束解剖重建MPFL,是一种安全、有效、可靠的治疗方法,能够获得满意的临床效果。     

Failure rate analysis and clinical outcomes of two different femoral tunnel positions using anteromedial portal technique in anterior cruciate ligament reconstruction

AimTo analyze two different femoral tunnel positions and to evaluate their correlation with clinical, functional outcomes and surgical revision rate in patients who underwent primary arthroscopic anterior cruciate ligament (ACL) reconstruction with anteromedial (AM) portal technique.MethodsFrom January 2015 to October 2018, we recruited 244 patients that underwent primary single-bundle ACL reconstruction, using four strand-semitendinosus graft and AM portal technique for femoral tunnel placement. Patients were divided into two groups based on the different femoral tunnel positions: 117 patients of group A had ACL footprint center femoral tunnel position compared with 127 patients of group B, with femoral tunnel placement close to the AM bundle footprint. Preoperatively and at last follow up, all patients were assessed subjectively by Lysholm, Tegner, and International Knee Documentation Committee (IKDC) scores, while Lachman, Pivot-shift, and KT-1000 tests were performed to evaluate knee joint stability.ResultsGroup B patients showed significantly better results in Lysholm, objective, and subjective IKDC scores compared with patients of group A (P < 0.001). A significantly higher surgical failure rate was found in group A than in group B (10.26% vs. 2.3%; P < 0.001). A higher anterior knee laxity was recorded in patients of group A than in patients of group B (1.9 ± 1.1 vs. 1.3 ± 1 mm; P < 0.001); a reduction in mean anterior tibial translation from preoperative to final follow up was found in group B compared with group A (3.5 ± 1.2 vs. 2.7 ± 1.1 mm; P < 0.001). No significant differences in the Tegner scale were found between the two groups.ConclusionACL reconstruction performed using the AM portal technique showed better and more satisfactory clinical and functional outcomes associated with a lower failure rate when the femoral tunnel had been placed more eccentrically in the footprint, in the AM bundle center position.     

Over-the-top Anterior Cruciate Ligament (ACL) reconstruction plus lateral plasty with hamstrings in high-school athletes: Results at 10 years

BackgroundAnterior Cruciate Ligament (ACL) injuries have grown in adolescent population in the last decades, and if surgical reconstruction resulted safe in the short term, its impact in the long term is still unclear. The purpose of this study was to assess the long-term risk of failure, the rate of contralateral injury and the clinical reported outcomes in a cohort of high-school athletes after ACL reconstruction.Methods54 consecutive patients (mean age 16.3 ± 1.4 years) underwent ACL reconstruction with a single-bundle plus lateral plasty hamstring technique between May 2006 and July 2009. The number of subsequent ipsilateral reoperations and contralateral ACL reconstruction, Lhysolm, KOOS, VAS for pain and Tegner Activity Level was determined at a minimum follow-up of 10 years.ResultsIpsilateral ACL revision was performed in 8 (3.4%) patients, contralateral ACL reconstruction in 11 (21.1%). The average Lysholm score was 95.1 ± 9.2. The average KOOS was 96.5 ± 6.3 for the Pain subscale, 92.2 ± 9.0 for the Symptom subscale, 99.2 ± 1.8 for the ADL subscale, 94.1 ± 10.1 for the Sport subscale and 91.8 ± 14.5 for the Quality-of-life subscale. The average VAS for pain during activity was 1.7 ± 2.3. 90% returned to sport, 15% decreased the activity level, 61% of patients were still involved in sport, 35% at the same pre-injury level.ConclusionAt long-term, single-bundle hamstring ACL-R plus lateral-plasty in a cohort of high school athletes resulted to have a comparable graft failure rate and contralateral ACL injury with other surgical techniques.     

Arthroscopic anterior cruciate ligament surgery: Results of autogenous patellar tendon graft versus the Leeds-Keio synthetic graft: Five year follow-up of a prospective randomised controlled trial

We conducted a prospective, randomised controlled trial comparing anterior cruciate ligament reconstruction using middle third patellar tendon graft (PT) to synthetic Leeds-Keio (LK) ligament. The patients were randomised (26 PT, 24 LK). Subjective knee function was classified (Lysholm, Tegner activity, IKDC scores), laxity was measured (Lachman test, Stryker laxometer), and functional ability was assessed (one-hop test).There were no significant differences between Lysholm or IKDC scores at any stage by 5 years. Significant differences were found between the groups at 2 years for Tegner activity scores, laxity and one-hop testing. By 5 years there were no significant differences. Clinical equivalence was demonstrated between the two groups for the Lysholm score and one-hop test but not for the Tegner activity score at 5 years.The use of the LK ligament has been largely abandoned due to reports of its insufficiency. Our results demonstrate that it is not as inferior as one might expect. We conclude that the results of LK ligament ACL reconstruction are as acceptable as those using PT. It may provide an additional means of reconstruction where no suitable alternative is present.     

Psychometric properties of the Norwich Patellar Instability Score in people with recurrent patellar dislocation

BackgroundPatellar dislocations account for two percent of all knee injuries with a 17% chance of re-dislocation. There are few validated scores specific to instability. One of these is the Norwich Patellar Instability Score. There has been limited assessment of the validity, floor-ceiling effect and responsiveness of the Norwich Patellar Instability (NPI) Score from an independent centre. The purpose of this paper is to address this limitation.MethodsData from 90 patients referred to a tertiary referral patellofemoral clinic were analysed. All routinely completed data including NPI Score, Kujala Patellofemoral Disorder Score, and demographic outcomes during appointments, up to 36 months following initial clinical assessment was analysed. Convergent validity was assessed by correlating outcomes of the Kujala Patellofemoral Disorder Score to the NPI Score. Effect size (ES) was determined between baseline to 12-month and 12 to 36-month assessments to determine responsiveness. Floor-ceiling effect was evaluated at baseline, 12-month and 12 to 36-month follow-up.ResultsNPI Score demonstrated good convergent validity to the Kujala Patellofemoral Disorder Score (p < .001; 95% confidence interval (CI): − 0.71 to − 0.52). NPI Score demonstrated good responsiveness to change both between baseline to 12 months (ES: 0.43; 95% CI: 0.42 to 0.10) and 12 to 36 months (ES: 0.67; 95% CI: 0.60 to 0.15). Whilst the NPI Score did not demonstrate a ceiling effect, there was moderate risk of a floor-effect where 13% of the cohort reported the lowest levels of NPI scores.ConclusionsThe NPI Score is a valid and responsive outcome for people with recurrent patellar dislocation.     

Ultrasonographic evaluation of the patellar tendon length and elasticity after open-wedge high tibial osteotomy: A comparison with radiological and clinical parameters

BackgroundThe aim of this study was to evaluate the length and elasticity of the patellar tendon after open-wedge high tibial osteotomy (OWHTO).MethodsThis case-controlled, analytical study included patients who underwent unilateral OWHTO operation and a control group. The length, thickness, strain elastography, and strain ratio of the patellar tendon were measured. The outcome measures were the Insall–Salvati Index (ISI), Blackburne–Peel Index (BPI), Caton Index (CI), the International Knee Documentation Committee Score (IKDC), Oxford Knee Score (OKS) and Knee Injury and Osteoarthritis Outcome Score (KOOS), Ahlbäck classification, and mechanical axis. Elasticity of the patellar tendon obtained by strain elastography were graded as follows; hardest or hard tissue, intermediate tissue, and soft tissue.ResultsThe patellar tendon length was significantly shorter and patellar tendon thickness was significantly greater on the operated side compared with the values of the non-operated side and the control group (P < 0.001 for all). Intermediate tissue was the most common elasticity grade (77%) for strain elastography on the operated side. Hardest tissue was the most common elasticity grade on the non-operated side of the patients (49.1%) and of the control group (70.0%). Patellar tendon length was correlated positively with IKDC, OKS, and KOOS values and patellar tendon thickness and strain ratio were correlated negatively with IKDC, OKS, and KOOS values.ConclusionThe patellar tendon seems to be shortened and thickened, with reduced stiffness after OWHTO. The ultrasound parameters are also associated with functional outcomes.     

Effect of medial–lateral malpositioning of the femoral component in total knee arthroplasty on anterior knee pain at greater than 8 years of follow-up

BackgroundThe trochlea is often medialized after total knee arthroplasty (TKA) resulting in abnormal patellar tracking, which may lead to anterior knee pain. However, due to the difference in shape of the natural trochlea and the patellar groove of the femoral component, a medialization of the femoral component of 5 mm results in an equal patellar position at 0–30° of flexion. We tested the hypothesis that more medialization of the trochlea results in a higher VAS pain score and lower Kujala anterior knee pain score at midterm follow-up.MethodsDuring surgery a special instrument was used to measure the mediolateral position of the natural trochlea and the prosthetic groove in 61 patients between 2004 and 2005. Patient reported outcome measures were used to investigate the clinical results (NRS-pain, NRS-satisfaction, KOOS-PS and Kujala knee score).ResultsIn total 40 patients were included. The mean follow-up was 8.8 years. A medialization of ≥ 5 mm resulted in a significantly lower NRS-pain (0.2 vs. 1.4; p = 0.004) and higher NRS-satisfaction (9.6 vs. 8.2; p = 0.045). Overall clinical results were good; KOOS-PS was 33.9 and Kujala knee score was 72.1.ConclusionsThe present study showed that a more medial position may result in a better postoperative outcome, which can probably be explained by the non-physiological lateral orientation of the trochlear groove in TKA designs.Level of evidence: Level III     

Influence of patient-related factors on clinical outcome of tibial tubercle transfer combined with medial patellofemoral ligament reconstruction

Background

Tibial tubercle transfer is frequently used for treating patellar instability. This study aimed to analyze the clinical results following tibial tuberosity transfer with medial patellofemoral ligament (MPFL) reconstruction in the treatment of patellar instability.

Conforming patellar button design improves outcome of total knee arthroplasty

BackgroundPatellar resurfacing is commonly performed during total knee arthroplasty (TKA), and the patellar button design can vary within a TKA implant. Implant design is known to affect patella kinematics, contact mechanics, and ultimately the outcome of TKA. The aim of this study was to compare the patient-reported outcomes of TKA with either a conforming (CP) or medialized dome (MD) patellar component.MethodsThe study was a prospective cohort study of 100 TKAs performed between December 2015 and August 2017. We compared a consecutive series of 50 TKA subjects with a CP, with the previous 50 TKA subjects with an MD patella. The primary outcome measure was difference in Knee Injury and Osteoarthritis Score (KOOS) at 12 months. Other patient-reported outcome measures included EQ5D as a general health measure, and patient satisfaction.ResultsThere was no significant difference in baseline characteristics, KOOS, or EQ5D between the two groups. At 12 months, the CP Group had a higher mean KOOS function score (87 vs. 80, P = 0.04), and greater patient satisfaction (98% vs. 82% satisfied, P = 0.009) compared with the MD group. The CP Group had significantly lower frequency of pain with level walking, less difficulty with stairs, and lower mean EQ5D mobility at 12 months compared with the MD group.ConclusionsTKA performed using a conforming patella has superior results over a medialized dome patellar component for KOOS function, patient satisfaction, walking pain, stair performance, and mobility at 12 months postoperatively. The differences observed with the change in patellar design may be unique to this prosthesis.