Fifteen-Year Minimum Follow-Up of Anteromedial Tibial Tubercle Transfer for Lateral and/or Distal Patellofemoral Arthrosis

Three-Dimensional Imaging of the Patellofemoral Joint Improves Understanding of Trochlear Anatomy and Pathology and Planning of Realignment

Three-dimensional (3D) modeling using digital or printed models provides a unique perspective that caters to cognitive spatial ability in a way that can add to our understanding and mental representations of human anatomy. This is particularly useful in the setting of trochlear dysplasia, where the morphology of the groove can exhibit substantial variability and complexity. Using 3D reformatted images and models, a pragmatic understanding of how morphology influences patellofemoral pathology can be gleaned. Further, this perspective facilitates cognition of what patellar tracking may look like after realignment procedures. Using 3D modeling, concepts such as patella alta, trochlear depth, lateralization of the patellar entry point, trochlear curvature, and the presence of a proximal trochlear spur can help afford a better understanding of how trochlear anatomy may influence tracking while also providing insight as to the ideal tracking path. The use of 3D has recently emerged as a useful tool in multiple surgical subspecialties, particularly in situations involving surgical planning or complex anatomy. Given the complexity and variation in trochlear morphology in patients with trochlear dysplasia who develop either patellar instability or focal overloading, 3D modeling is well-suited to provide a perspective that can add to our understanding of trochlear dysplasia, and potentially even how we diagnose and treat it. LEVEL OF EVIDENCE: Level V, expert opinion.

Detailed Assessment of Confounders is Necessary for Valid Interpretation of the Results in Patellofemoral Cartilage Restoration Studies

Cartilage restoration procedures have gained increased traction over the years as a treatment for chondral defects in relatively younger patients. A critical assessment of study populations for confounders is vital in order to interpret results in a valid manner. This is particularly true when assessing outcomes of cartilage restoration procedures in the patellofemoral compartment given substantial heterogeneity amongst patients within study populations. Patients often undergo additional procedures (prior or concomitant), have variable anatomy (malalignment, maltracking, and trochlear dysplasia), and variable chondral defect sizes, depths, and locations (lateral patellar facet, medial patellar facet, median patellar ridge, trochlea). Without an assessment of study populations for potential confounders that may influence the results, limited conclusions can be gleaned from any results pertaining to the outcomes of cartilage restoration procedures within the patellofemoral joint. Finally, there are many choices for cartilage restoration (osteochondral autografting, osteochondral allografting, autologous chondrocyte implantation, autologous matrix-induced chondrogenesis and PJAC), different clinical situations where one may confer benefit over the other, yet all seem to result in significant improvement for patients with acceptable failure rates.

Occupational and Functional Outcomes following Patellofemoral Arthroplasty in U.S. Military Servicemembers

The functional outcomes in patients undergoing patellofemoral arthroplasty (PFA) with high occupational demands have not been fully examined. This study assessed return to work and conversion to TKA rates following PFA in a young, military cohort. Patient demographics, pain scores, and surgical information were retrospectively collected for all active-duty military members who underwent PFA over a 4-year period. The data were then analyzed to calculate return to work, conversion to TKA, and perioperative complications rates. A total of 48 servicemembers with 60 total PFAs (36 unilateral, 12 bilateral) were included, with a mean follow up of 2.2 years. At the final follow-up, 83% of servicemembers returned to military service or completed their service obligation after PFA. Conversion to TKA occurred in three (6.2%) patients at an average of 2.4 years after PFA, resulting in a PFA annual revision rate of 2.3%. The mean numeric rating scale for pain improved from 4.9 ± 2.6 at baseline to 2.5 ± 2.0 postoperatively (p < 0.001). Servicemembers with at least one prior ipsilateral knee procedure had a significantly decreased odds ratio (OR) for both occupational outcome failure (OR, 0.03; 95% confidence interval [CI], 0-0.29) and overall failure (OR, 0.13; 95% CI, 0.02-0.78). At an average of 2 years following PFA, 83% of military members returned to duty, with a low rate of revision to TKA. Prior ipsilateral knee procedure decreased the probability of medical separation. LEVEL OF EVIDENCE:  IV.

Early Postoperative Complications and Associated Variables After Tibial Tubercle Osteotomy: A 15-Year Experience From a Single Academic Institution

Background

Tibial tubercle osteotomy (TTO) is a well-established surgical treatment option for patients with patellofemoral disorders.

Purpose

To determine the rate of early (≤90 day) postoperative complications after TTO and variables related to postoperative complications.

Study Design

Case series; Level of evidence, 4.

Methods

Patients who underwent TTO at a single academic institution within a 15-year period (2008-2022) were identified. All patients with a minimum 90-day follow-up were considered for study inclusion. Exclusion criteria were age younger than 14 years and revision surgery. Patient characteristics, surgical history, and concomitant procedures were identified, and risk factor analysis was performed to identify variables associated with early postoperative complications.

Results

A total of 344 knees in 313 patients met eligibility criteria and were included in the final analysis. One intraoperative complication (0.3%), a premature closure of the incision before repair of the vastus medialis, was identified. There were 141 postoperative complications (138 surgical, 3 medical) in 118 patients for a complication rate of 34.3%. The most common complications were stiffness requiring a nonstandard-of-care intervention (16.3%), superficial wound infection/wound dehiscence (8.1%), and hemarthrosis/effusion requiring aspiration (5.8%). Patients experiencing postoperative complications were older (mean difference, 3.49 years; 95% CI, 1.26-5.73 years; P = .002), had a higher mean Charlson Comorbidity Index (mean difference, 0.26; 95% CI, 0.08-0.45; P = .006), and were more likely to be current smokers (P = .015) compared with patients with no complications. Inpatient surgery (defined as surgery in a hospital setting with at least 1 overnight stay) was associated with postoperative complications (odds ratio [OR], 2.29; 95% CI, 1.39-3.77; P = .001); this association remained significant generation of a multivariate model (OR, 2.07; 95% CI, 1.19-3.58; P = .010). Previous surgery on the ipsilateral knee (P < .001) and concomitant autologous chondrocyte implantation (P = .046) were also associated with postoperative complications.

Conclusion

The study findings indicated a low intraoperative complication rate (0.3%) and a relatively high early postoperative (≤90 day) complication rate (34.3%) after TTO. Variables associated with postoperative complications included greater age, higher Charlson Comorbidity Index, surgery in an inpatient setting, previous surgery on the ipsilateral knee, and concomitant autologous chondrocyte implantation.

Revision lateralization osteotomy of the tibial tubercle has excellent outcomes in patients suffering from previous medial tibial tubercle overcorrection

INTRODUCTION

Tibial tubercle osteotomy (TTO) is a common procedure used to treat patients with patellofemoral instability (PFI) and osteoarthritis (PFOA). Medial patellar maltracking due to previous excessive medialization of the tibial tubercle has rarely been reported. Therefore, the goal of this study was to assess patient-reported outcome measures (PROMs) after revision osteotomy with lateralization of the tibial tubercle (RL-TTO) to correct medial patellofemoral maltracking.

MATERIALS AND METHODS

Between 2017 and 2021, a series of 11 patients (male/female 1/10; age 35.8 ± 10.5 years) were treated by RL-TTO, of whom 8 patients could be retrospectively evaluated after a mean of 32.4 ± 15.1 months (range 18-61 months) postoperatively. The Kujala anterior knee pain scale, the patellofemoral subscale of the Knee Osteoarthritis and Outcome Score (KOOS-PF), and a numeric analog scale (NAS; 0-10) regarding anterior knee pain (AKP) at rest and during activity were assessed from pre- to postoperatively.

RESULTS

The preoperative mean tibial tubercle-trochlear groove (TT-TG) and tibial tubercle-posterior cruciate ligament (TT-PCL) distances were - 6.5 ± 6.5 mm and 0.7 ± 4.6 mm, respectively. The intraoperatively determined amount of tibial tubercle lateralization averaged 10.7 ± 3.6 mm. The Kujala score and KOOS-PF improved significantly from 33.6 ± 10.1 (23-51) points to 94.4 ± 6.2 points (82-100) (p < 0.001) and from 20.6 ± 13.2 points (0-43.3) to 87.3 ± 9.9 points (72.8-100) (p < 0.001) from pre- to postoperatively, respectively. Pain at rest decreased from 5.8 ± 1.9 to 0.8 ± 0.9 (p < 0.001), and pain during activity decreased from 8.6 ± 1.3 to 1.6 ± 1.5 (p < 0.001).

CONCLUSION

RL-TTO significantly improved subjective knee function and AKP in patients suffering from medial patellar maltracking due to previous excessive tibial tubercle medialization osteotomy at short-term follow-up.

The remaining parameters of patellar instability could be affected for osteoarthritic change after medial patellofemoral ligament reconstruction with or without anteromedialization of the tibial tubercle osteotomy for patellar instability: a retrospective cohort study

BACKGROUND

In literature, studies evaluating the factors associated the postoperative progression of patellofemoral (PF) osteoarthritis (OA) following patellar stabilization surgery are limited. This study aimed to compare the clinical outcomes after medial patellofemoral ligament reconstruction (MPFLR) as an isolated procedure (iMPFLR) and in combination with anteromedialization (AMZ) of the tibial tubercle osteotomy (TTO) and investigate the factors related to the postoperative progression of PFOA after patellar stabilization surgery.

METHODS

Between 2009 and 2020, 30 knees of 23 consecutive patients underwent MPFLR with or without AMZ, using an autologous semitendinosus tendon graft; they were followed up for more than 2 years in the retrospective nature of the study. iMPFLR was performed in cases of recurrent patellar dislocation with normal tibial tubercle-trochlear groove (TT-TG) distance and no PFOA, and MPFLR+AMZ was performed for cases of excessive TT-TG distance, preoperative PFOA of recurrent patellar dislocation, or habitual patellar dislocation. Clinical findings and radiographs of the PF joint were evaluated pre- and postoperatively with PF alignment parameters and PFOA and were compared between surgical procedures. Factors for the postoperative progression of PFOA were compared between the OA progression and non-progression groups.

RESULTS

Postoperative clinical score, radiographic parameters except for sulcus angle, TT-TG distance, and progression of PFOA were not significantly different between the iMPFLR and MPFLR+AMZ groups. Postoperative lateral patellar displacement (p = 0.001) and congruence angle (p = 0.017) were significantly different between the OA progression and non-progression groups.

CONCLUSION

Similar to MPFLR for recurrent cases, MPFLR with AMZ can improve the clinical and radiographic outcomes in severe cases. The remaining parameters of patellar instability could be affected in the postoperative progression of PFOA after MPFL reconstruction with or without AMZ of TTO for patellar instability.

High incidence of complication following tibial tubercle surgery

OBJECTIVES

Tibial tubercle osteotomy (TTO) is a common procedure that is frequently used in the treatment of recurrent patellar instability and/or patellar chondrosis. Current estimates of TTO complications in the literature vary widely, with complication rates reaching 59 percent. This variability is due, in part, to inconsistent definitions of complication between studies. The purpose of this study was to identify our complication rate following TTO procedures, with sub-analysis of whether the complication rate was affected by: 1. An intra-articular component defined as an additional procedure that altered post-operative rehabilitation and 2. A distalization of the tubercle translation.

METHODS

All patients between May 2009 and May 2015 who underwent a TTO were retrospectively identified. Complications were defined as major (fracture of the tibia, deep infection, non-union, delayed union, arthrofibrosis, deep vein thrombosis (DVT) and loss of screw fixation) versus minor (superficial wound infection, disturbance of cutaneous sensation and delay in wound healing). Subgroup analysis of distalization versus no distalization and intra-versus extra-articular concomitant procedures were also analysed.

RESULTS

One hundred and sixty-three TTOs in 150 patients were included in the final cohort with a mean follow-up of 21.3 months. The overall complication rate was 35 major complications (21.5%) and 13 minor complications (8.0%), with a total complication rate of 29.5 percent. TTO distalization did not increase the rate of complications. DVT was only seen in the intra-articular procedure cohort (n = 3/1.8%). Arthrofibrosis was the most common complication, occurring in 17 knees.

CONCLUSION

The overall complication rate of TTOs was 29.5%, with arthrofibrosis (10.4%) as the largest complication. DVT increased with concomitant intra-articular procedure. Distalization of the tubercle compared to no distalization had no significant effect on complications.

LEVEL OF EVIDENCE

Retrospective Cohort study, level III.

After Chondroplasty, Patient Election to Proceed With Cartilage Transplantation Is Closely and Additively Associated With Preoperative AMADEUS (Area Measurement And DEpth Underlying Structure) Grade, Condylar Involvement, Knee Injury and Osteoarthritis Outcome Score Pain Score, and Veterans Rand 12-Item Health Survey Physical Score

Purpose

To identify risk factors for patient election to proceed with cartilage transplant after staging chondroplasty.

Methods

This study retrospective reviewed patients prospectively enrolled at the time of staging chondroplasty, with early election defined as patient decision to proceed to cartilage transplantation within 6 months of chondroplasty. Cox proportional hazards analysis was used to determine univariate predictors of conversion, and a predictive calculator, the Cartilage Early Return for Transplant score, was formulated using stepwise regression employing the Akaike information criterion. Receiver operator curves and the area under the curve were used to evaluate the predictive ability of the final model on the studied patient population.

Results

Sixty-five knees (63 patients) were evaluated, with an overall transplant election rate of 27.7% within 6 months after chondroplasty. Based on multivariate results, the final Akaike information criterion-driven Cartilage Early Return for Transplant score employed preoperative Knee Injury and Osteoarthritis Outcome Score Pain Score, Veterans Rand 12-Item Health Survey Physical Score, condylar involvement, and AMADEUS (Area Measurement And DEpth Underlying Structure) score to generate a 0- to 7-point risk-stratification system with a 3% early election to proceed to transplant risk in the 0- to 2-point score group, 33% risk in the 3- to 4-point group, and 79% risk in the 5+-point group (P < .01) and an overall AUC of 0.906 (P < .01).

Conclusions

Risk of early patient election to pursue cartilage transplantation after chondroplasty is closely and additively associated with preoperative AMADEUS grade, condylar involvement, Knee Injury and Osteoarthritis Outcome Score Pain Score, and Veterans Rand 12-Item Health Survey Physical Score.

Clinical Relevance

Understanding risk factors for conversion to cartilage transplantation may improve preoperative planning and counseling prior to staging chondroplasty.

Older age and varus alignment lead to early failure in treating patellofemoral osteoarthritis with Fulkerson osteotomy

Background: It is unclear the risk factors for the failure of modified Fulkerson osteotomy. Methods: We retrospectively reviewed 40 patients who underwent the modified Fulkerson osteotomy from 1998 to 2015. There were 4 males and 36 females. The mean age of the study group was 50.2 ± 11.2 years. We used standard anteriorization measuring 10-15 mm and medialization measuring 10 mm while maintaining an intact periosteal sleeve. Results: Both the patellofemoral angle and the congruence angle improved significantly after 5.9 years. Preoperatively, the mean preoperative Lysholm score was 56.12, and the Knee Society score was 60.52. At the final follow-up, these scores improved significantly to 88.75 and 86.49, respectively. However, eight patients (20%) underwent total knee arthroplasty in the follow-up period, five of whom underwent the operation within 5 years. Comparing the survival and non-survival groups, there was a significant difference of an older age in the TKA conversion group (survival: 48.3 ± 11.1; non-survival: 57.8 ± 8.7, p = 0.03). For knee alignment, the non-survival group had a mean valgus femorotibial angle of 1.8° ± 4.9° preoperatively, and the survival group had a mean valgus angle of 6.4° ± 4.5° (p = 0.03). Conclusions: we found that patients with older age and those with varus alignment have an increased risk of deteriorated medial femorotibial cartilage.

Influence of Articular Geometry and Tibial Tubercle Location on Patellofemoral Kinematics and Contact Mechanics

Trochlear groove geometry and the location of the tibial tubercle, where the patellar tendon inserts, have both been associated with patellofemoral instability and can be modified surgically. Although their effects on patellofemoral biomechanics have been investigated individually, the interaction between the two is unclear. The authors' aim was to use statistical shape modeling and musculoskeletal simulation to examine the effect of patellofemoral geometry on the relationship between tibial tubercle location and patellofemoral function. A statistical shape model was used to generate new knee geometries with trochlear grooves ranging from shallow to deep. A Monte Carlo approach was used to create 750 knee models by randomly selecting a geometry and randomly translating the tibial tubercle medially/laterally and anteriorly. Each knee model was incorporated into a musculoskeletal model, and an overground walking trial was simulated. Knees with shallow trochlear geometry were more sensitive to tubercle medialization with greater changes in lateral patella position (-3.0 mm/cm medialization shallow vs -0.6 mm/cm deep) and cartilage contact pressure (-0.51 MPa/cm medialization shallow vs 0.04 MPa/cm deep). However, knees with deep trochlear geometry experienced greater increases in medial cartilage contact pressure with medialization. This modeling framework has the potential to aid in surgical decision making.

Coronal Malalignment-When and How to Perform a Tibial Tubercle Osteotomy

Coronal malalignment of the patellofemoral joint may contribute to both instability as well as pain and joint overload. The use of distal realignment procedures has evolved to include uniplanar and multiplanar osteotomies, which allows patient-specific treatment. With a careful understanding of the complex pathoanatomy, including osseous, soft tissue, and dynamic muscular factors, an appropriately designed tibial tubercle osteotomy (TTO) is an invaluable tool for the orthopedic surgeon to improve joint biomechanics and off-load articular injuries. Current techniques have improved TTO surgery to limit complications and produce reliably good results.

Tibial Tubercle Osteotomy May Not Provide Additional Benefit in Treating Patellar Dislocation With Increased Tibial Tuberosity-Trochlear Groove Distance: A Systematic Review

PURPOSE

To examine the indications and outcomes of medial patellofemoral ligament reconstruction (MPFLR) with or without tibial tubercle osteotomy (TTO) in treating recurrent or habitual patellar dislocation with an increased tibial tuberosity-trochlear groove (TT-TG) distance.

METHODS

We performed a literature search of the established medical databases Cochrane Central, PubMed-MEDLINE, EMBASE, and Web of Science. The inclusion criteria were as follows: skeletally mature patients with recurrent or habitual patellar dislocation and an increased TT-TG distance, treatment with MPFLR combined with a TTO procedure or isolated MPFLR, and reporting of clinical outcomes and complications. Each study was assessed for quality and the level of evidence. The general characteristics, indications, surgical techniques, TT-TG distance, clinical results, imaging evaluation findings, and complications of each study were recorded.

RESULTS

Nine studies consisting of 288 knees met the inclusion criteria. The average Coleman score was 71.56 (range, 55-83). The threshold for an increased TT-TG distance ranged from 16 to 20 mm in the included studies. Similar good postoperative outcomes were reported in patients with an increased TT-TG distance treated with MPFLR with versus without a TTO procedure. The mean postoperative Lysholm score ranged from 75.0 to 94.7 (I² = 87.6%) in the isolated MPFLR group and from 85.0 to 87.6 (I² = 16.3%) in the TTO-with-MPFLR group. Similar postoperative congruence angles were reported in both groups. The postoperative redislocation rate ranged from 0% to 4.2% in the TTO-with-MPFLR group, and no redislocation was found in the isolated MPFLR group. The postoperative apprehension sign was only reported in isolated MPFLR patients.

CONCLUSIONS

The outcomes of MPFLR with or without TTO to treat recurrent or habitual patellar dislocation with an increased TT-TG distance appeared similar. However, this study was limited by the considerable heterogeneity, variety of techniques, variety of TT-TG distances, and variability in patella alta and trochlear dysplasia among the included studies.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II to IV studies.

Tibial tubercle transfer leads to clinically relevant improvement in patients with patellar maltracking without instability: a systematic review and meta-analysis

PURPOSE

To assess the different surgical techniques and their outcomes following tibial tubercle transfer (TTT) in patients with patellar maltracking.

METHODS

A systematic search of the literature was performed in PubMed, EMBASE and Cochrane Library. Studies reporting patient-reported outcome measures (PROMs) or clinical outcome following: TTT in patients with patellar maltracking were included. Collected PROMs were Lysholm, Kujala, IKDC score, and VAS pain. Clinical outcome included reported clinical success, patient satisfaction, complications and removal of hardware (ROH). Overall pre-, post-operative and change scores were estimated using random-effects meta-analysis models. Results were reported as overall mean and per transfer direction.

RESULTS

A total of 26 studies and 761 patients (818 knees, mean age 35 years, mean follow-up 5.0 years) were included. In 73% of the studies, surgery was performed after failed conservative treatment. Transfer direction was anteromedial in 76% of all procedures. Overall Lysholm score improved from 61 to 91, Kujala from 52 to 85, IKDC from 53 to 81, and VAS from 6.2 to 2.5, respectively. Clinical success was reported in 79% of patients, and 80% of patients reported to have satisfactory results. Rates of complications and ROH were 13% and 29%, respectively.

CONCLUSIONS

TTT for management of patellar maltracking can lead to good results with clinically meaningful improvement, an overall clinical success of 79% and overall patient satisfaction of 80% when appreciating the underlying anatomic condition and using appropriate technique. The level of evidence was low, and large-scale prospective, comparative cohort studies with uniform outcome scales are needed to confirm these findings.

LEVEL OF EVIDENCE

IV.

[Expert consensus on surgical treatment of patellofemoral osteoarthritis]

Patellofemoral osteoarthritis (PFOA) is one of the most common causes of anterior knee pain in middle-aged and elderly population. In general, elementary therapy and drug therapy are the preferred choices for PFOA management. However, for those who cannot achieve satisfactory effectiveness with standard non-surgical treatment, surgical therapy stands as an alternative treatment. The surgical therapy includes repair surgery and reconstruction surgery. The choice of surgical plans for PFOA management mainly depends on the etiology, pathogenesis, location, and severity of the lesions. To aid clinical decision-making, the National Clinical Research Center for Geriatric Disorders (Xiangya Hospital) and the Joint Surgery Branch of the Chinese Orthopedic Association arranged nationwide orthopedic specialists to set up a work panel. After reviewing the research progress of surgical therapy and the latest guidelines and consensus for PFOA management, the work panel discussed repeatedly to reach this consensus. The present consensus aims to provide valid evidences for clinical practices of the surgical therapy of PFOA, so as to avoid inappropriate and irregular treatment behaviors, reduce surgical trauma, improve surgical efficacy and the quality of life, and to ease the burden of PFOA.