Tibial Tuberosity-trochlear Groove Research Articles

Decreased Effective Patellar Tendon Length following Distalization Tibial Tubercle Osteotomy without Patellar Tendon Tenodesis.

Distalization tibial tubercle osteotomy (TTO) is an effective treatment for improving patellar height in patients with patella alta associated with patellofemoral instability and cartilage lesions. The addition of a patellar tendon tenodesis has been suggested; nonetheless, concerns exist regarding possible increased patellofemoral cartilage stresses. To evaluate pre- and postoperative patellar tendon length and alignment parameters on magnetic resonance imaging (MRI), as well as patient-reported outcome measures (PROMs) after distalization TTO without patellar tendon tenodesis. Case series; Level of evidence, 4. Twenty skeletally mature patients who underwent distalization TTO with or without anteromedialization at our institution between December 2014 and August 2021 were included. All patients underwent pre- and postoperative MRIs of the affected knee. The Caton-Deschamps index (CDI), the axial and sagittal tibial tubercle-trochlear groove (TT-TG) distances, the distances from the tibial plateau to the patellar tendon insertion and the tibial tubercle, and the patellar tendon length were assessed. PROMs included the International Knee Documentation Committee Subjective Knee Evaluation Form, the Knee injury and Osteoarthritis Outcome Score-Quality of Life subscale, the Kujala Anterior Knee Pain Scale, and the Veterans RAND 12-Item Health Survey mental and physical component scores. The mean patient age at surgery was 27.4 years (range, 14-42 years). Radiographic parameters demonstrated improved patellar height (CDI decreased from 1.36 to 1.11; P < .001) after distalization TTO. The distance from the tibial plateau to the patellar tendon insertion significantly decreased from 20.1 mm preoperatively to 17.9 mm postoperatively (P < .020), and the patellar tendon length decreased from 53.4 mm preoperatively to 46.0 mm postoperatively (P < .001). The patellar tendon insertion was not distalized after distalization TTO, likely because of scarring of the patellar tendon proximal to the osteotomy site. Patients demonstrated significant pre- to postoperative improvements on all PROMs (P≤ .024 for all ). There were 4 (20%) complications-2 cases of arthrofibrosis, 1 postoperative infection, and 1 osteotomy delayed union. Distalization TTO without patellar tendon tenodesis was associated with improved radiographic outcomes and PROMs. It provides an additional tool for surgical management of patellofemoral pathology with associated patella alta.

Combination of tibial tubercle transfer, medial patellofemoral ligament reconstruction, trochleoplasty and lateral release for patellofemoral instability provides good middle- to long-term outcomes in adolescents.

There are limited studies that have reported the middle- to long-term outcomes of combined procedures consisting of more than two procedures for patellofemoral instability. The current study aims to investigate and report the middle- to long-term outcomes of a combination procedure of tibial tubercle transfer, medial patellofemoral ligament reconstruction, trochleoplasty and lateral release for patellofemoral instability in patients aged 18 years and below. In the cohort study, all patients aged 18 years old or younger who underwent a combination procedure of tibial tubercle transfer, medial patellofemoral ligament reconstruction, trochleoplasty and lateral release for recurrent patellofemoral instability were included. A total of 21 patients were included in the study. All patients had no further patellofemoral dislocation, pain and apprehension following the 4-in-1 surgery (p < 0.01). There was a significant improvement in the Kujala score from 36.1 (SD 12.9) pre-operatively to 93.1 (SD 3.6) post-operatively (p < 0.001). The patients also had a statistically significant improvement in their radiological factors, including the patellar tilt angle (p < 0.001), sulcus angle (p = 0.001), trochlear groove depth (p = 0.041), tibial tubercle-trochlear groove distance (p < 0.001) and Caton-Deschamps index (p = 0.001). A combination procedure of tibial tubercle transfer, medial patellofemoral ligament reconstruction, trochleoplasty and lateral release leads to good middle- to long-term subjective, functional and radiographic outcomes for patients with recurrent patellofemoral instability and underlying predisposing factors of increased TT-TG distance of more than 20mm, Dejour B or D trochlear dysplasia and medial patellofemoral ligament rupture. IV.

Tibial tuberosity-trochlear groove distance is significantly decreased by medial closing wedge distal femoral osteotomy.

While medial closing wedge distal femoral osteotomy (MCWDFO) has been used to address patella instability combined with valgus malalignment, its impact on patellofemoral parameters remains uncharted. Hence, this study seeks to establish a three-dimensional (3D) planning of MCWDFO and measure its effect on the tibial tubercle - trochlear groove distance (TTTG) through simulation and calculation. MCWDFO with a stepwise increment of one-degree varisation (1°-15°) was performed on 3D surface models of 14 lower extremities with valgus malalignment and 24 lower extremities with neutral alignment of the lower limb, resulting in a total of 608 simulations. Anatomic landmarks were employed to measure hip-knee-ankle angle (HKA), TTTG, and femoral torsion for each simulation. A mathematical formula was adopted to calculate TTTG changes following MCWDFO, and subsequently the mean simulated and calculated TTTG values were compared. Following a standardised protocol, MCWDFO was performed without rotational changes. MCWDFO exhibited an almost linear reduction in TTTG, at a rate of approximately -1.05 ± 0.13 mm per 1° of varisation, demonstrating a strong negative correlation (R = -0.83; p < 0.001). Limb alignment did not exert an influence on TTTG change; however, it correlated with tibial plateau width. The mean difference between the simulated and calculated TTTG values amounted to 0.03 ± 0.03 mm per 1° varisation (p < 0.001). The TTTG distance is linearly reduced by 1.05 mm for every 1° of varisation within the varus correction range of 0°-15° during MCWDFO. Patients with combined valgus and patellar instability may benefit from MCWDFO due to frequently pathological TTTG. Level III, descriptive laboratory study.

Patients who undergo tibial tubercle anteromedialization with medial patellofemoral ligament reconstruction demonstrate similar rates of return to sport compared to isolated MPFL reconstruction.

To investigate the rate of return to sports and sport psychological readiness between patients who underwent isolated MPFLR (iMPFLR) compared to a matched cohort of patients who underwent MPFLR with anteromedializing tibial tubercle osteotomy (MPFLR/TTO). Patients who underwent primary MPFLR with or without TTO for recurrent patellar instability were retrospectively reviewed from 2012 to 2020 at a single institution. Preinjury sport and work information, Kujala, Tegner, Visual Analogue Scorefor pain, satisfactionand MPFL-Return to Sport after Injury (MPFL-RSI) score were collected. Two readers independently measured the tibial tuberosity-trochlear groove distance, Caton-Deschamps indexand Dejour classification for trochlear dysplasia. Patients in iMPFLR and MPFLR/TTO groups were matched 1:1 on age, sex, body mass indexand follow-up length. Multivariate regression analysis was performed to determine whether the MPFL-RSI was associated with a return to sport. This study included 74 patients at mean follow-up of 52.5 months (range: 24-117). These groups returned to sport at similar rates (iMPFLR: 67.6%, MPFLR/TTO: 73.0%, not significant [ns]), though iMPFLR patients returned more quickly (8.4 vs. 12.8 months, p = 0.019). Rates of return to preinjury sport level were also similar (45.9% vs. 40.5%, ns). Patients with Dejour B/C took more time to return to sport compared to patients with mild/no trochlear pathology (13.8 vs. 7.9 months, p = 0.003). Increasing MPFL-RSI score was significantly predictive of the overall return to sport (odds ratio [OR]: 1.08, 95% confidence interval [CI] [1.03, 1.13], p < 0.001) and return to preinjury level (OR: 1.07, 95% CI [1.04, 1.13], p < 0.001). Most patients in iMPFLR and MPFLR/TTO groups resumed work (95.7% vs. 88.5%, ns), though iMPFLR patients who returned to preinjury work levels did so more quickly (1.7 vs. 4.6 months, p = 0.005). Patients who underwent MPFLR with anteromedializing TTO demonstrated similar rates of return to sport and psychological readiness compared to an isolated MPFLR matched comparison group, though iMPFLRs returned more quickly. Patients with more severe trochlear pathology required more time to return to sports. Level III.

Comparison of Failure Rates at Long-term Follow-up Between MPFL Repair and Reconstruction for Recurrent Lateral Patellar Instability.

The medial patellofemoral ligament (MPFL) is the primary soft tissue restraint to lateral patellar translation and is often disrupted by lateral patellar dislocation. Surgical management for recurrent patellar instability focuses on restoring the MPFL function with repair or reconstruction techniques. Recent studies have favored reconstruction over repair; however, long-term comparative studies are limited. To compare long-term clinical outcomes, complications, and recurrence rates of isolated MPFL reconstruction and MPFL repair for recurrent lateral patellar instability. Cohort study; Level of evidence, 3. A total of 55 patients (n = 58 knees) with recurrent lateral patellar instability were treated between 2005 and 2012 with either MPFL repair or MPFL reconstruction. The exclusion criteria were previous or concomitant tibial tubercle osteotomy or trochleoplasty and follow-up of <8 years. Pre- and postoperative descriptive, surgical, imaging, and clinical data were recorded for each patient. MPFL repair was performed on 26 patients (n = 29 knees; 14 women, 15 men), with a mean age of 18.4 years. MPFL reconstruction was performed on 29 patients (n = 29 knees; 18 women, 11 men), with a mean age of 18.2 years. At a mean follow-up of 12 years (range, 8.3-18.9 years), the reconstruction group had a significantly lower rate of recurrent dislocation compared with the repair group (14% vs 41%; P = .019). There were no differences in the number of preoperative dislocations or tibial tubercle-trochlear groove distance. The reconstruction group had significantly more time from initial injury to surgery compared with the repair group (median, 1460 days vs 627 days; P = .007). There were no differences in postoperative Tegner, Lysholm, or Kujala scores at the final follow-up. In addition, no statistically significant differences were detected in return to sport (RTS) rates (repair [81%] vs reconstruction [75%]; P = .610) or reoperation rates for recurrent instability (repair [21%] vs reconstruction [7%]; P = .13). MPFL repair resulted in a nearly 3-fold higher rate of recurrent patellar dislocation (41% vs 14%) at the long-term follow-up compared with MPFL reconstruction. Given this disparate rate, the authors recommend MPFL reconstruction over repair because of the lower failure rate and similar, if not superior, clinical outcomes and RTS.

Association between patellofemoral osteoarthritis with demographic features and anatomical variants of the knee in non-traumatic patients

Background: Patellofemoral osteoarthritis (PFOA) is a common cause of knee discomfort and impairment, particularly among athletes. The development of PFOA has been associated with anatomical knee variations, such as trochlear dysplasia and patella alta. However, the relationship between these anatomical variants and the development of PFOA remains poorly understood. This study aimed to investigate the association between PFOA and knee anatomical variants in a cohort of patients. Methods: The study included 200 patients with PFOA and 200 healthy controls. In this study, we investigate the relationship of osteoarthritis with both anatomical variants and demographic characteristics. The participants underwent Magnetic resonance imaging (MRI) evaluation of the knee, and anatomical variants including trochlear dysplasia and patella alta were assessed. The severity of PFOA was also graded based on cartilage area and depth, as well as the bone marrow involvement and presence of osteophytes. Results: Statistically significant differences were observed between the two groups in terms of Tibial tuberosity-trochlear groove (TT-TG) distance, patella position, trochlear dysplasia, and Insall-Salvati ratio. The mean TT-TG distance, prevalence of alta patella position, and Insall-Salvati ratio were significantly higher in cases (P&lt;0.001 for all), and cases had a higher incidence of trochlear dysplasia (P&lt;0.001). There were no significant differences between cases and controls regarding patella baja. Conclusion: Anatomical knee variants, including the TT-TG distance, trochlear dysplasia, and Insall-Salvati ratio, are significant risk factors for PFOA progression. The results also indicate that higher BMI and older age are significantly associated with more measures of MRI Osteoarthritis Knee Score (MOAKS) than demographic information. Among anatomical variants, a higher TT-TG distance and an increased grade of trochlear dysplasia show a significant relationship with more measures of MOAKS. Understanding the relationship between these factors has important clinical and research implications and can help inform the development of new treatments.

Does Tibial Tuberosity Osteotomy Improve Outcomes When Combined With Medial Patellofemoral Ligament Reconstruction in the Presence of Increased Tibial Tuberosity-Trochlear Groove Distance? A Systematic Review and Meta-analysis.

There has been recent debate regarding the optimal surgical management strategy for recurrent patellofemoral instability in the presence of an increased tibial tuberosity-trochlear groove (TT-TG) distance. In particular, performing a combined tibial tuberosity osteotomy (TTO) and medial patellofemoral ligament reconstruction (MPFLR) for patients with a TT-TG >20 mm has been questioned, with the hypothesis that an isolated MPFLR (iMPFLR) would be just as effective. To pool and compare outcomes after MPFLR+TTO versus iMPFLR in patients with a TT-TG >20 mm. Systematic review; Level of evidence, 4. PubMed-MEDLINE, Embase, Web of Science, and Cochrane Central were searched, and a systematic review was performed. Included were studies that reported postoperative redislocation rates and/or functional outcome scores for patients with recurrent patellar instability and a TT-TG >20 mm who underwent either MPFLR+TTO or iMPFLR and had minimum 2-year follow-up data. Methodologic quality was assessed using the modified Coleman Methodology Score (mCMS). A proportional meta-analysis comparing redislocation, subjective instability, and total complication rates was performed, and mean postoperative functional outcome scores were pooled using a random-effects model with a restricted maximum likelihood estimator. In total, 1548 studies were screened, from which 13 were included for analysis. Of the 386 included patients (406 knees), 276 underwent MPFLR+TTO and 110 underwent iMPFLR. The mean mCMS was 61.3 ± 10.5 (range, 48-77). The pooled postoperative redislocation rate was 1.22% (95% CI, 0.22%-7%), with no significant difference between the study groups (P = .9995). The pooled complication rate was 10.17% (95% CI, 6.2%-16.3%) with no difference between groups (P = .9275), although the MPFLR+TTO group had higher heterogeneity in complication rates (I2 = 79.4%) compared with iMPFLR (I2 = 0%). There was no group difference in the pooled postoperative Lysholm scores (P = .5177), but patients who underwent iMPFLR had significantly higher postoperative Kujala scores compared with those who underwent MPFLR+TTO (P = .0283). Even in the presence of previously indicative anatomic factors (TT-TG >20 mm), TTO combined with MPFLR does not seem to confer additional benefit compared with iMPFLR. This finding could be advantageous in minimizing the burden of additional surgery with its associated risks. The study findings should, however, be interpreted with caution given the heterogeneity of the studies.

Correlation of tibial tuberosity–trochlear groove distance, anterolateral ligament injury, and the type of trochlear dysplasia with the grade of anterior cruciate ligaments tear

BackgroundThe anterior cruciate ligament (ACL) is the most frequently injured ligament. The grade of ACL tear on magnetic resonance imaging (MRI) can help determine the ACL injury treatment. Lateralization of the tibial tubercle is indicated by an increase in the distance of the tibial tuberosity–trochlear groove (TT-TG). Anterolateral ligament (ALL) injury affects a high degree of pivot shift in the knee joint with ACL deficiency. Trochlear dysplasia (TD) is a congenital morphological deformity of the femoral trochlea. An increase in the TT-TG distance, as well as the presence of ALL injuries and TD, can elevate the likelihood of experiencing ACL injuries. This study aims to analyze the correlation of TT-TG distance, ALL injury, and type of TD with the grade of ACL tear through MRI.MethodsThis analytical cross-sectional study was conducted from November 2021 to June 2022 at RSUP Dr. Kariadi Hospital, Semarang. The ACL tear was divided into three degrees. The Schoettle or the Nizić method was used to measure the TT-TG distance. ALL injuries were evaluated by looking at the integrity of the ligament. TD assessment was according to the Dejour classification.ResultsA total of 50 subjects participated in the study. The TT-TG distance for grade I ACL tears was 5.90–14.6 mm (22%), 1.69–18.30 mm (44%) for grade II, and 1.01–14.10 mm (34%) for grade III. The ANOVA test showed no significant relationship between the TT-TG distance and the degree of ACL tear (p = 0.146). ALL injuries were found in six study subjects: One subject (16.7%) had grade I ACL tear, three subjects (50%) had grade II, and two subjects (33.3%) had grade III. The Chi-square test showed no significant correlation between ALL injuries and the degree of ACL tear (p = 0.930). Most subjects did not experience TD (78%), while 20% experienced TD type A and 2% experienced TD type B. In type A TD, 50% of ACL tears were grade I, 30% grade II, and 20% grade III. Among all subjects with TD type B, only one was found to have a grade III ACL tear. Based on the Chi-square test, there was no significant correlation between TD type and the degree of ACL tear (p = 0.110).ConclusionsThere is no significant correlation between the tibial tuberosity–trochlear groove distance, ALL injury, and type of trochlear dysplasia with the grade of ACL tear.

Quadriceps tendon malalignment is an independent anatomical deformity which is the primary abnormality associated with lateral facet patellofemoral joint osteoarthritis.

The purposes of this study are to, firstly, develop techniques to accurately identify extensor mechanism malalignment by measuring the alignment of the quadriceps tendon (QTA) with computerized tomography (CT) scans. Secondly, to investigate correlations between QTA and lower limb bony anatomical variations within a representative normal population. Lastly, to evaluate the clinical significance of QTA by establishing its potential connection with lateral facet patellofemoral joint osteoarthritis (LFPFJOA). CT scans were orientated to a mechanical axis reference frame and three techniques developed to measure the alignment of the quadriceps tendon. Multiple measurement of bony alignment from the hip to the ankle were performed on each scan. A series of 110 cadaveric CT scans were measured to determine normal values, reproducibility, and correlations with bony anatomy. Secondly, a comparison between 2 groups of 25 patients, 1 group with LFPFJOA and 1 group with isolated medial OA and no LFPFJOA. From the cadaveric study, it was determined that the alignment of the quadriceps tendon is on average 4.3° (SD 3.9) varus and the apex of the tendon is 9.1mm (SD 7.7mm) lateral to the trochlear groove and externally rotated 1.9° (SD 12.4°) from the centre of the femoral shaft. There was no association between the quadriceps tendon alignment and any other bony measurements including tibial tubercle trochlear groove distance (TTTG), coronal alignment, trochlear groove alignment and femoral neck anteversion. A lateralized QTA was significantly associated with LFPFJOA. QTA in the LFPFJOA group was 9.6° varus (SD 2.8°), 21.3mm (SD 6.6) lateralised and 17.3° ER (SD 11°) compared to 5.5° (SD 2.3°), 10.7mm (SD 4.9) and 3.3° (SD 7.2°), respectively, in the control group (p < 0.001). A significant association with LFPFJOA was also found for TTTG (17.2mm (SD 5.7) vs 12.1mm (SD 4.3), p < 0.01). Logistic regression analysis confirmed the QTA as having the stronger association with LFPFJOA than TTTG (AUC 0.87 to 0.92 for QTA vs 0.79 for TTTG). These studies have confirmed the ability to accurately determine QTA on CT scans. The normal values indicate that the QTA is highly variable and unrelated to bony anatomy. The comparative study has determined that QTA is clinically relevant and a lateralised QTA is the dominant predictor of severe LFPFJOA. This deformity should be considered when assessing patella maltracking associated with patella osteoarthritis, patella instability and arthroplasty. III (retrospective cohort study).

Length Changes of the Medial Patellofemoral Ligament During In Vivo Knee Motion: An Evaluation Using Dynamic Computed Tomography

Background: Medial patellofemoral ligament (MPFL) reconstruction is associated with high complication rates because of graft overloading from incorrect graft positioning. To improve clinical outcomes, it is crucial to gain a better understanding of MPFL elongation patterns. Purpose: To assess MPFL length changes in healthy knees from 0° to 90° of dynamic flexion and their relationship with anatomic parameters of the patellofemoral joint. Study Design: Descriptive laboratory study. Methods: Dynamic computed tomography scans of an active flexion-extension-flexion movement in 115 knees from 63 healthy participants were evaluated to construct knee joint models. Using these models, the MPFL length was measured as the shortest wrapping path from the Schöttle point on the femur to 3 insertion points on the superomedial border of the patella (proximal, central, and distal). MPFL length changes (%) relative to the length in full extension were calculated, and their correlations with the tibial tuberosity–trochlear groove distance, Caton-Deschamps index, and lateral trochlear inclination were analyzed. Results: The proximal fiber was the longest in full extension and progressively decreased to a median length of −6.0% at 90° of flexion. The central fiber exhibited the most isometric pattern during knee flexion, showing a median maximal decrease of 2.8% relative to the full extension length and no evident elongation. The distal fiber first slightly decreased in length but increased at deeper flexion angles. The median overall length changes were 4.6, 4.7, and 5.7 mm for the proximal, central, and distal patellar insertion, respectively. These values were either not or very weakly correlated with the tibial tuberosity–trochlear groove distance, Caton-Deschamps index, and lateral trochlear inclination when the anatomic parameters were within the healthy range. Conclusion: The median MPFL length changed by approximately 5 mm between 0° and 90° of flexion. Proximally, the length continuously decreased, indicating slackening behavior. Distally, the length increased at deeper flexion angles, indicating tightening behavior. Clinical Relevance: In MPFL reconstruction techniques utilizing the Schöttle point to establish the femoral insertion, one should avoid distal patellar insertion, as it causes elongation of the ligament, which may increase the risk for complications due to overloading.

Anteromedial Tibial Tubercle Osteotomy for Recurrent Patella Subluxation

Background: Patellofemoral pathology resulting from improper biomechanics is difficult to treat, and lateral patellar instability requires individualized treatment, which may include tibial tubercle osteotomy (TTO) with anteromedial repositioning. Indications: Symptomatic patellofemoral instability with maltracking, particularly in cases with a tibial tuberosity-trochlear groove distance &gt;16 mm. Technique Description: We describe an oblique osteotomy from medial to lateral. A careful completion of the osteotomy is made with an osteotome, and the resulting fragment is mobilized to achieve anteromedial repositioning—as well as distalization in cases of patella alta. Two bicortical screws with a washer are used for fixation of the tibial tubercle following anteromedialization. Results: Systematic reviews demonstrated that the treatment of the lateral patellar instability requires an individual treatment and the anteromedial TTO is a very important procedure alone or in association with medial patellofemoral ligament. Discussion/Conclusion: Recurrent lateral patellar instability is a challenging condition with complex causes and various treatment options, but anteromedial TTO provides an effective way to improve clinical outcomes and correct patellar maltracking, with relatively low complication rates. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Predicting the Probability of Recurrence Based on Individualized Risk Factors After Primary Lateral Patellar Dislocation Treated Nonoperatively

To develop a comprehensive and effective personalized scoring system on the basis of demographic and clinical characteristics for predicting recurrence probability in patients with primary lateral patellar dislocation (LPD). Participants included 261 primary patients with LPD with 2-year minimum follow-up from our hospital across 2013 to 2020. Demographic and clinical characteristics were collected retrospectively. The backward stepwise method was performed to identify independent predictors and construct a nomogram to predict the probability of recurrence. The predictive performance was assessed by receiver operating characteristic curves, calibration plots, and decision curve analysis. After variables selection, 6 independent predictors of recurrence (skeletal maturity, trochlear dysplasia, tibial tuberosity-trochlear groove distance, mechanical axis deviation, Insall-Salvati index, and patellar tilt) were enrolled in our model. Validation of this nomogram in both training and validation cohort revealed powerful predictive ability, with an area under the curve of 0.962 and 0.977, respectively. The nomogram also showed great calibration and good clinical practicability. Our study presented a nomogram that incorporates 6 independent risk factors (skeletal maturity, trochlear dysplasia, tibial tuberosity-trochlear groove distance, mechanical axis deviation, Insall-Salvati index, and patellar tilt), which can be conveniently used to accurately predicts the risk of recurrence after primary LPD in individual cases. Level III, retrospective comparative prognostic study.

Miserable malalignment syndrome associated knee pain: a case for infra-tubercle tibial de-rotation osteotomy using an external fixator

IntroductionMiserable malalignment syndrome is a complex torsional lower limb deformity with limited consensus on surgical treatment. We present the outcome of de-rotation of the tibia alone using an external fixator.MethodsFifteen patients (22 segments) were operated on between 2012 and 2020; 13 presented with anterior knee pain, and two presented with out-toeing. Gait analysis was done in nine patients, and CT scan rotational profile, including tibial tubercle–trochlear groove distance, femoral version, and tibial torsion, were calculated. Kujala knee pain score and visual analogue pain score (VAS) were recorded. All underwent infra-tubercular osteotomy of the tibia and midshaft osteotmy of the fibula and application of a hexapod circular frame to gradually internally rotate the tibia until the foot aligned with the patella.ResultsThere was no preoperative clinical or radiographic evidence for patellar instability, femoral anteversion 30° (21°–54°), and external tibial torsion 50° (37–70). The mean age at surgery was 21 years (12–37) with a mean follow-up of 20 months (9–83). All osteotomies healed, and the frames were removed at a mean of 111 days (80–168). The mean VAS score improved from 8(5–9) to 1(0–4) postoperatively (P < 0.001). The mean Kujala knee pain score increased from 53 (30–75) to 92 (54–100) postoperatively (P < 0.001). The mean preoperative foot progression angle (FPA) was 37° (20°–50°), with 13 postoperatively walking with neutral FPA. One patient walked with symmetrical + 10° and the other with − 5° FPA. All patients reported relief of knee pain and were satisfied with the alignment.ConclusionGradual correction of severe external tibia torsion with a hexapod external fixator and an infra-tubercle tibial osteotomy could provide an optimum method to eliminate knee pain and improve limb alignment in miserable malalignment syndrome.

PATELLOFEMORAL INSTABILITY MANAGEMENT IN A PROSPECTIVE PAEDIATRIC COHORT IN EDINBURGH

Patellofemoral instability (PFI) is a common cause of knee pain and disability in the paediatric population. Patella alta, lateralised tibial tubercle, medial patellofemoral ligament (MPFL) deficiency, genu valgum and trochlear dysplasia are well known risk factors.A prospective database was created including patients referred through our physiotherapy pathway following first-time patella dislocation. Patella alta and lateralisation of the tibial tuberosity was treated with a Fulkerson-type tibial tubercle osteotomy(TTO). Medial patellofemoral ligament was reconstructed using quads tendon autograft pull-down technique. A modified Sheffield protocol was used postoperatively allowing weightbearing in a hinged knee brace.Forty patients were identified with 8 patients having bilateral presentations. Male to female ratio was 12:28 with an age range of 4–17 years. Eight patients had congenital PFI, five patients acquired PFI through traumatic patella dislocation and twenty-seven patients developed PFI from recurrent dislocations. Structural abnormalities were found in 38(95%) of patients. Patella alta (Caton-Deschamps index &gt;1.2) was identified in 19(47%) patients, genu valgum in 12(30%) patients, increased tibial tubercle-trochlear groove distance(TT-TG&gt;20mm) was present in 9(22.5%) patients and persistent femoral anteversion(&gt; 20 deg) in 7(17%) patients.Eight patients were treated with TTO and MPFL reconstruction, three patients with MPFL reconstruction alone and five patients had guided growth for genu valgum correction. Ten patients are awaiting surgery. No postoperative patients had recurrence of PFI at their latest follow up.PFI is a common problem in the adolescent paediatric population with identifiable structural abnormalities. Correcting structural pathology with surgery leads to predictable and safe outcomes.

Increased TT-TG distance caused by excessive tibiofemoral rotation predicts poor clinical outcomes after tibial tubercle osteotomy in recurrent patellar dislocation.

To compare clinical outcome between recurrent patellar dislocation (RPD) with or without actual tibial tubercle lateralisation (TTL) after medial patellofemoral ligament reconstruction (MPFL-R) combined with tibial tubercle transfer. From 2015 to 2018, a total of 172 knees with RPD and a tibial tubercle-trochlear groove (TT-TG) distance of > 20 mm were treated with MPFL-R combined with tibial tubercle transfer. Patients were divided into the lateralisation group (TT-PCL > 24 mm, n = 74) and the nonlateralisation group (TT-PCL ≤ 24 mm, n = 60) based on the presence or absence of actual TTL (TT-PCL > 24 mm). Clinical outcomes were assessed postoperatively at a minimum of 2 years. Second-look arthroscopic evaluations were available for 84 knees to assess cartilage damage. A total of 134 knees with a median follow-up time of 32 months were included. Tibiofemoral rotation (TFR) was significantly higher in the nonlateralisation group than in the lateralisation group (15.4° vs. 9.4°, P < 0.001). At the final follow-up, the nonlateralisation group had significantly lower Kujala (78.2 vs. 86.4, P = 0.001) and Lysholm (80.3 vs. 88.2, P = 0.003) scores than the lateralisation group. At the time of the second-look arthroscopic assessment, 38.9% of the patients in the nonlateralisation group showed cartilage worsening in the medial patellar facet that was significantly higher than that in the lateralisation group (38.9% vs. 12.5%, P = 0.015). Patients with RPD and an increased TT-TG distance of > 20 mm but without actual tibial tubercle lateralisation benefit less from tibial tubercle transfer than patients with actual tibial tubercle lateralisation, which may be related to the significantly higher tibiofemoral rotation angle of the former. III.

Association of Hip Dysplasia With Trochlear Dysplasia in Skeletally Mature Patients.

Developmental dysplasia of the hip (DDH) and trochlear dysplasia (TD) are distinct pathologies with several important features in common. In addition to shared risk factors, both forms of dysplasia cause abnormal joint kinematics and force transmission, predisposing patients to pain, injuries to cartilage and soft tissue stabilizers, and ultimately arthritis. To evaluate for an association between hip dysplasia and TD in skeletally mature patients with symptomatic hip dysplasia. Cross-sectional study; Level of evidence, 3. A total of 48 patients with DDH who underwent periacetabular osteotomy were compared with 48 sex-matched patients who underwent hip arthroscopy for femoroacetabular impingement (FAI) between July 2014 and February 2021. All patients were skeletally mature. The Tönnis angle and lateral center-edge angle were measured on preoperative pelvis radiographs. Femoral version, trochlear depth, lateral trochlear inclination (LTI), tibial tubercle-trochlear groove distance (TTTG-d), and posterior lateral condylar angle (PLCA) were measured on preoperative magnetic resonance imaging scans of the symptomatic hip and ipsilateral knee. Continuous variables were compared between the patient groups using 2-sample t tests. Interobserver reliability was measured using the intraclass correlation coefficient. Patients with DDH demonstrated a reduced trochlear depth compared with patients with FAI (3.6 vs 4.6 mm; P < .001). There were no differences between groups in femoral anteversion, LTI, TTTG-d, or PLCA. Two (4.2%) patients with FAI and 17 (35.4%) patients with DDH had a trochlear depth <3 mm (P < .001). One (2.1%) patient with FAI and 7 (14.6%) patients with DDH had an LTI <11° (P = .027). There was no difference between groups in frequency of a convex proximal trochlea, patient-reported ipsilateral knee pain, or ipsilateral knee procedures. Patients with DDH had reduced trochlear depth compared with patients with FAI, demonstrating a higher incidence of dysplastic trochlear features that may predispose patients to patellofemoral joint disease. Further research is needed to determine whether screening at-risk patients and treating TD will help to prevent symptomatic patellofemoral disease.

Tibial Tuberosity Rotation in Patients With Patellar Instability Versus Age- and Sex-Matched Controls.

Several methods have been described to measure external rotation of the tibial tuberosity; all use femoral landmarks. To develop reproducible tibial-based methods to measure external rotation of the tibial tuberosity in patients with patellar instability. Cross-sectional study; Level of evidence, 3. Included were magnetic resonance images of 61 patients with patellar instability and 61 age- and sex-matched healthy controls. Three novel methods using tibial landmarks to measure the rotation of the tibial tuberosity (plateau axis-tuberosity axis [PA-TA] angle, tibial geometric center-tuberosity axis [GC-TA] angle, and plateau axis-midtuberosity point [PA-MT] angle) as well as a femoral-based rotational measurement (surgical transepicondylar axis-tuberosity axis [sTEA-TA] angle) and the tibial tuberosity-trochlear groove (TT-TG) distance were measured and compared in instability patients and controls using unpaired t tests, and the cutoff values for predicting instability were calculated using receiver operating characteristic curves. The correlations between the angle measurements and the TT-TG distance were analyzed. Instability patients had significantly higher external rotation of the tibial tuberosity compared with controls with regard to the PA-TA angle (18.2° ± 9.6° versus 13.1° ± 6.8°; P = .001), GC-TA angle (8.4° ± 4.5° versus 11.5° ± 3.9°; P = .0001) and sTEA-TA angle (122° ± 8.5° versus 113.6° ± 6.3°; P = .0001). The mean TT-TG distance was also significantly higher in the instability group (18.2 ± 5.4 versus 11.5 ± 2.7 mm; P = .001). The cutoff values were 17.5° (area under the receiver operating characteristic curve [AUC] = 0.66) for PA-TA angle, 8.5° (AUC = 0.705) for GC-TA angle, 118.8° (AUC = 0.79) for sTEA-TA angle, and 15.2 mm for TT-TG distance (AUC = 0.863). PA-TA angle was significantly correlated with all other measurements (r = 0.35-0.71; P ≤ .006 for all), whereas sTEA-TA angle had the strongest correlation with TT-TG distance (r = 0.78; P = .001). The tibial tuberosity was externally rotated in patellar instability patients compared with age- and sex-matched controls, and this intrinsic malalignment of the proximal tibia was demonstrated in the tibial-based measurements.

TT-TG distance decreases after open wedge distal femoral varization osteotomy in patients with genu valgum & patellar instability. A pilot 3D computed tomography simulation study

BackgroundGenu valgum is considered to be a risk factor for patellar instability. Correction of valgus alone or combined with a tibial tuberosity medialization has been described. However, changes occurring in the tibial tuberosity-trochlear groove (TT-TG) distance after a lateral distal femoral opening wedge osteotomy (LDF-OWO) are not known.PurposeThis study aimed to define changes in TT-TG distance with increasing amounts of valgus correction after LDF-OWO.MethodsThree-Dimensional Computed Tomography (3D-CT) scans of six patients (two females and four males) aged between 19 and 35 years with genu valgum and patellar instability were analyzed. 3D models of femoral, tibial, and patellar bones were created with the advanced segment option of Mimics 21® software. An oblique lateral opening wedge osteotomy of the distal femur was simulated in 2-degree increments up to 12 degrees of varus opening. Change in TT-TG distance was measured in mm on 3D models of the knee.ResultsCompared to baseline without osteotomy, the TT-TG distance decreased significantly (p < 0.05) for all corrections from 2 to 12 degrees in 2° steps. The TT-TG distance decreased by an average of 1.7 mm for every 2 degrees of varus opening.ConclusionLateral opening wedge distal femoral osteotomy causes a decrease in TT-TG distance. The surgeon should be aware of the magnitude of this change (1.7 mm decrease for every 2° increment of valgus opening).

A Combined Surgical Approach for Recurrent Patellar Dislocation in Adolescents With Patella Alta and Increased Tibial Tuberosity-Trochlear Groove Distance: Improved Clinical Outcomes but Decreased Posterior Tibial Slopes in Skeletally Immature Patients at Minimum 4-Year Follow-Up

Purpose(1) To report the clinical and radiological outcomes of a surgical technique combining anatomic medial patellofemoral ligament (MPFL) reconstruction and tibia tuberosity transfer in adolescents with patella alta and elevated tibial tuberosity-trochlear groove (TT-TG) distance, in the treatment of recurrent patellar dislocation (RPD); (2) To investigate the potential risks of growth arrest or developmental deformities associated with this combined technique. MethodsMedical records of patients underwent the combined surgery were reviewed from 2015 to 2019. This study included adolescents aged between 14 and 18 years with a Caton-Deschamps index (CDI) greater than 1.30 and TT-TG distance greater than 20mm, with a minimum follow-up of 4 years. Radiological examinations including lateral views and full-length posteroanterior standing radiographs were investigated to assess patella height by CDI, posterior tibia slope (PTS) angle, side-to-side difference (SSD) in bone length, and lower extremity alignment by hip-knee-ankle (HKA) angle; CT-scans and MRI profiles were investigated to evaluate TT-TG distance and staging of growth plate closure. Other evaluations included preoperative and postoperative physical examination, Kujala score, and Tegner activity score. The patients were stratified into 3 subgroups according to a MRI-based staging system of the growth plate closure, and each outcomes were analyzed. A cohort-specific minimal clinically important difference (MCID) estimation was performed using standard error of measurement. ResultsThe average age at the time of surgery was 16.1 years (range, 14.1-17.8). The average follow-up was 5.6 years (range, 4.0-7.6). No recurrent dislocation occurred, no clinically significant deformity or axis deviation was encountered. Postoperative patellar height by CDI was 1.00±0.11 (range, 0.81-1.15). No significant differences were found in pre- and postoperative HKA angle and SSD in femur/tibia length among all subgroups. A significantly decreased PTS angle was found in patients with open growth plates, from 10.2±1.7° preoperatively to 8.1±1.0° postoperatively (P=.015). The Kujala score and Tegner score both significantly improved, from 65.5±13.9 preoperatively to 90.4±7.2 postoperatively in Kujala score (P <0.001), and from 4.0±1.1 preoperatively to 4.7±1.3 postoperatively in Tegner score (P <0.001). Of the whole cohort, 63.1%, 100%, 47.1% and 94.1% patients achieved the MCID for PTS angle, CDI, Tegner score, and Kujala score respectively. ConclusionThis combined technique is safe and effective in treating RPD in skeletally mature adolescents with concurrent patella alta (CDI > 1.30) and TT-TG distance > 20mm, permitting patients to have improved knee function and low complication rates. Nonetheless, patients with open growth plates demonstrated a decrease in PTS, which might predispose the knee to recurvatum and osteoarthritis in the long-term. Study DesignRetrospective therapeutic case series; level of evidence, Ⅳ.

Results of Medial Patellofemoral Ligament Reconstruction with and without Tibial Tubercle Transfer in Patellar Instability: A Systematic Review and Meta-Analysis.

The optimal surgical intervention for lateral patellar instability remains a topic of controversy despite satisfactory clinical outcomes and low re-dislocation rates reported in numerous studies following medial patellofemoral ligament reconstruction (MPFLR) with and without tibial tubercle transfer (TTT). The purpose of this systematic review and meta-analysis is to investigate the hypothesis that combining MPFLR with TTT provides reduced complication rates and improved clinical outcomes to isolated MPFLR in patients with lateral patellar instability. We conducted a comprehensive systematic review and meta-analysis of comparative trials involving MPFLR with and without TTT, sourcing data from PubMed, the Cochrane Library, Embase, and Web of Science. The primary clinical outcomes analyzed included the Kujala score, the Lysholm score, complication rates, and the Caton-Deschamps index (CDI). Random or fixed effects were used for the meta-analysis. Postoperatively, there were no significant differences observed in the Kujala and Lysholm scores between MPFLR and MPFLR + TTT (p = 0.053). At the final follow-up, the CDI had decreased 0.015 (95% CI -0.044, 0.013; p = 0.289) points in the MPFLR group, with no statistical significance. In contrast, the MPFLR + TTT group demonstrated a significant decrease of 0.207 (95% CI -0.240, -0.174; p = 0.000) points in CDI. Notably, the complication rate was higher in the MPFLR + TTT group compared to the MPFLR-only group (RR = 2.472; 95% CI 1.638, 3.731; p = 0.000). Both MPFLR and MPFLR + TTT procedures yield significant improvements in the Kujala and Lysholm scores. However, the MPFLR + TTT approach results in an apparent improvement in CDI and corrects patellar maltracking, particularly in cases involving high tibial tuberosity-trochlear groove (TT-TG) (>20 mm) or patella alta (CDI > 1.2), while MPFLR alone cannot. It is essential to consider the higher complication rate of MPFLR + TTT, which suggests that MPFLR alone may be sufficient for patients without high TT-TG or patella alta.