Outcomes following quadriceps tendon repair using transosseous tunnels versus suture anchors: A systematic review

Primary Repair of Complete Quadriceps Tendon Rupture with Extensor Mechanism Deficit

Background

Whereas partial quadriceps tendon ruptures may be treated nonoperatively if the extensor mechanism remains functional, complete ruptures require primary operative repair to achieve optimal functional results1,2. The 2 most common techniques are the use of transosseous tunnels and the use of suture anchors. The goal of these procedures is to reconstruct and restore mobility of the extensor mechanism of the leg.

Description

The patient is positioned supine with the injured leg exposed. A midline incision to the knee is made over the quadriceps tendon defect, exposing the distal quadriceps and proximal patella. Irrigation is utilized to evacuate the residual hematoma, and the distal quadriceps and proximal patella are debrided of degenerative tissue. When utilizing transosseous tunnels, a nonabsorbable suture is passed full-thickness through the medial or lateral half of the quadriceps tendon in a locked, running pattern (i.e., Krackow). A second nonabsorbable suture is passed full-thickness through the other half of the tendon. There should then be 4 loose strands at the distal quadriceps. The anatomic insertion of the quadriceps tendon is roughened with a sharp curet to expose fresh cancellous bone. Three parallel bone tunnels are created along the longitudinal axis of the patella. The knee is placed in full extension, with a bump under the heel in order to provide slight recurvatum at the knee and to allow for a properly tensioned repair. In pairs, the free ends of the sutures are passed through the tunnels. The sutures are tensioned and tied together in pairs at the distal aspect of the patella. Alternatively, when utilizing suture anchors, Arthrex FiberTape is passed full-thickness through the medial or lateral half of the quadriceps tendon in a Krackow pattern. A second FiberTape is passed full-thickness through the other half of the tendon. There should then be 4 loose tails at the distal quadriceps. The 2 tails of the medial FiberTape are placed into a knotless Arthrex SwiveLock anchor; this step is repeated for the 2 lateral tails. The anatomic insertion of the quadriceps tendon is roughened to expose fresh cancellous bone. With use of a 3.5-mm drill, create 2 parallel drill holes along the longitudinal axis of the patella, with sufficient depth to bury the SwiveLock anchor. Unlike in the transosseous tunnel technique, these drill holes do not run the length of the patella. The holes are then tapped. Following irrigation, the anchors are tensioned into the bone tunnels, and extra tape is cut flush to the bone. For both techniques, additional tears in the medial and lateral retinacula are repaired if present.

Alternatives

Alternatives include nonoperative treatment with use of a hinged knee brace; operative treatment with use of simple sutures; and augmentation with use of wire reinforcement, cancellous screws, the Scuderi technique, the Codivilla technique, tensor fasciae latae reinforcement, and/or MERSILENE tape (Ethicon).

Rationale

Primary operative repair of quadriceps tendon ruptures is a well-documented, successful procedure with biomechanical, clinical, and patient-reported data to support its use3-7. However, literature comparing the 2 most common surgical techniques remains controversial. Transosseous tunnel repair is the most common technique utilized to repair quadriceps tendon ruptures, but suture anchors have become increasingly popular in the past several years1,4. Most studies have reported no significant difference in biomechanical, clinical, and patient-reported outcome measures between these 2 techniques3,4,8-10. Decreased operative time and a smaller incision have been suggested as advantages of suture anchors4,9. However, this method incurs a higher average cost of surgery and risks a more complex revision in the event of deep infection9,10. Simple suture repair is a less commonly utilized technique and is now reserved for midsubstance tendon repairs. Nonoperative treatment of complete quadriceps tendon rupture is exceedingly rare and not recommended because of the profound functional consequences. Relative indications for nonoperative treatment include a patient who is unfit for surgery, is not ambulatory at baseline, or retains full extensor mechanism function. Nonoperative treatment is typically reserved for partial quadriceps ruptures and typically involves early immobilization with a hinged knee brace.

Expected Outcomes

Primary repair of quadriceps tendon ruptures, utilizing either the transosseous tunnel or suture anchor technique, yields excellent outcomes. Following surgical treatment, patients have near-full recovery in range of motion, with studies reporting a <5° deficit compared with the contralateral, uninjured limb3,4,10,11. The vast majority of patients (>90%) return to pre-injury levels of function and work3,4,7,11. The majority of patients also report satisfactory results, as assessed with use of patient-reported outcome measures3,4,10. The most commonly reported complications are knee stiffness and quadriceps muscle atrophy, which can both be treated with proper rehabilitation. Even in the event of these complications, however, patients can maintain adequate knee function2,3. More severe complications are rare (<3%) and include deep venous thrombosis and/or pulmonary embolism, superficial and/or deep infection, and tendon rerupture2-4,10-12. Delayed operative treatment is associated with worse outcomes and increased complication rates1,3,4,10,11.

Important Tips

When performing the Krackow stitch, be sure to tension and remove all slack before performing another tissue pass.Surgical repair should be performed as soon as possible from the time of injury in order to minimize risks and to achieve optimal surgical outcomes.If there is concern that the primary construct would be unstable, it can be augmented with wire reinforcement, cancellous screws, the Scuderi technique, the Codivilla technique, tensor fasciae latae reinforcement, and/or MERSILENE tape.Identify and repair patellar retinaculum tears, which are common concomitant injuries in the setting of complete quadriceps rupture.

Acronyms and Abbreviations

MRI = magnetic resonance imaging.

Similar Outcomes Are Found Between Quadriceps Tendon Repair With Transosseous Tunnels and Suture Anchors: A Systematic Review and Meta-Analysis

Purpose

To evaluate the clinical outcomes and biomechanical performance of transosseous tunnels compared with suture anchors for quadriceps tendon repair.

Methods

In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic search was performed in April 2021 in the following databases: Cochrane Database of Systematic Reviews, PubMed (1980-2021), MEDLINE (1980-2021), Embase (1980-2021), and CINAHL (1980-2021). Level I-IV studies were included if they provided outcome data for surgical repair of the quadriceps tendon using transosseous tunnels or suture anchors with minimum 1-year follow-up. Biomechanical studies comparing transosseous tunnels and suture anchors were separately analyzed.

Results

The systematic search yielded 1,837 citations, 23 of which met inclusion criteria (18 clinical, 5 biomechanical). In total, 13 studies reported results for transosseous repair and 7 studies reported results for repair with suture anchors. There were results for 508 patients from clinical studies. The average postoperative Lysholm score ranged from 88 to 92 for suture anchor repairs and 72.8 to 94 for transosseous repairs with range of motion ranging from 117° to 138° and 116° to 135°, respectively. Synthesis of the biomechanical data revealed the mean difference in load to failure was not significant between constructs (137.21; 95% confidence interval -10.14 to 284.57 N; P = .068).

Conclusions

Transosseous and suture anchor techniques for quadriceps tendon repair result in similar biomechanical and postoperative outcomes. No difference between techniques in regard to ultimate load to failure among comparative biomechanical studies were observed.

Level of Evidence

Level IV, systematic review level III-IV studies.

Quadriceps Tendon Delamination Tear: A Case Report

Partial quadriceps tendon ruptures are rare and they are usually managed non-operatively, provided that the extensor mechanism is intact. In case the extension mechanism is compromised, a more aggressive treatment is required, which includes surgical repair of the tendon. We present an extremely rare case of a 42-year-old male lifter who sustained a quadriceps tendon delamination tear, after lifting weights. Careful clinical examination revealed a compromised extension mechanism of the knee. Proper imaging confirmed the diagnosis of partial but significant rupture of the undersurface of the quadriceps tendon, which was treated operatively (standard tendon repair with the Krakow technique and three transosseous tunnels) with a very good outcome.

Adjustable Cortical Fixation Repair Is a Safe and Effective Technique for Quadriceps Tendon Rupture

Purpose

To report the clinical outcomes of quadriceps tendon repair using adjustable cortical fixation devices at a minimum 2-year follow-up.

Methods

A retrospective chart review identified patients who underwent quadriceps tendon repair using adjustable cortical fixation devices between January 2017 and March 2020. Patients with a partial tendon rupture were excluded. Demographic and injury-specific variables were gathered preoperatively and postoperatively from the electronic medical record and patient-reported outcomes (Lysholm Knee Questionnaire, Lower Extremity Functional Scale, and SF-12) were collected via telephone at a minimum of 2 years postoperatively.

Results

Fourteen quadriceps tendon repairs were included in a total of 13 patients. The average time to follow-up was 3.5 ± 1.2 years with a range of 1.9 to 5.7 years. The mean age of this cohort was 55.7 ± 11.6 years, and the mean body mass index was 32.9 ± 6.0. Ten injuries (71.4%) were sustained by mechanical fall, 2 patients (14.3%) suffered a direct blow to the knee, and 2 patients (14.3%) reported a noncontact injury mechanism. Thirteen quadriceps ruptures (13/14, 92.9%) underwent surgery within 10 days of their injury. One knee (7.1%) had a postoperative extensor lag of 5°, whereas another knee (7.1%) required a reoperation for manipulation under anesthesia and arthroscopic lysis of adhesions at 3 months' postoperatively. None of the included patients (0.0%) developed a tendon re-rupture, venous thromboembolism, delayed wound healing, surgical-site infection, neuropraxia or nerve injury, hardware irritation, patella fracture, or heterotopic ossification.

Conclusions

In this study, adjustable cortical fixation was a safe and effective surgical technique for quadriceps tendon repair, with adequate restoration of quadriceps function and a low rate of adverse events at 2 years postoperatively.

Level of Evidence

Level IV, therapeutic case series.

Editorial Commentary: Quadriceps Tendon Suture Anchor Repair Provides Better Patient-Reported Outcomes Than Transosseous Tunnel Repair: Defining the New Gold Standard

Quadriceps tendon suture anchor repair provides biomechanically greater and more consistent failure loads than transosseous tunnel repair, including less cyclic displacement (gap formation). Although satisfactory clinical outcomes are found with both repair techniques, few studies provide a side-to-side comparison. However, recent research demonstrates better clinical outcomes in using suture anchors, with equal failure rates. Suture anchor repair is minimally invasive requiring smaller incisions, less patellar dissection, and eliminates patellar tunnel drilling that can breach the anterior cortex, create stress risers, result in osteolysis from nonabsorbable intraosseous sutures and longitudinal patellar fractures. Suture anchor quadriceps tendon repair should now be considered the gold standard.

Use of the forgotten joint score (FJS)-12 to evaluate knee awareness after quadriceps tendon reconstruction

BACKGROUND

Quadriceps tendon rupture (QTR) is a severe injury of the knee extensor apparatus. The study aims to validate the use of forgotten joint score (FJS-12) for functional outcome assessing after surgical treatment of QTR.

METHODS

Fifty-seven patients who underwent surgery for QTR with transosseous suture reconstruction in a single orthopaedic surgery and traumatology center between 2015 and 2020 were eligible for enrolment in this retrospective case series. The demographic data and other pre-operative details such as age, gender, comorbidities and medication use also were extracted from the medical records. Patient reported outcome measures (PROMs) were gathered in the form of Western Ontario and McMaster Universities Arthritis Index Score (WOMAC), Tegner Activity Score (TAS), Lysholm Score and FJS-12 at a mean follow-up time of 49.84 months ± 20.64 months. The FJS-12 was validated by correlation with WOMAC, TAS and Lysholm Score.

RESULTS

The mean age of all patients were 69.2 ± 13.6 years with 51 (89.5%) males and 6 (10.5%) females. The mean time from injury to surgery was 3.39 ± 5.46 days. All patients reported satisfactory functional outcomes after surgery on FJS-12, WOMAC and Lysholm scores, except the TAS, which decreased slightly from pre-operative level. There was a high negative correlation between WOMAC and FJS-12, but moderate positive correlations between FJS-12 and TAS and Lysholm scores. The Cronbach's alpha value was 0.96 for 12 items in FJS-12.

CONCLUSION

This study has found that FJS-12 is a reliable and easy to assess tool for functional outcomes after QTR reconstruction. It has shown moderate to strong correlation with other commonly used outcome measures (WOMAC, TAS and Lysholm).

Re-tensionable Quadriceps Tendon Repair Technique

Quadriceps tendon rupture is a devastating injury that has traditionally been repaired using bone tunnels and knot tying. Recent innovations seeking to address persistent weakness and gap formation of repairs have used suture anchors and knotless technology. Despite these innovations, the clinical outcomes of these repairs continue to be mixed. We describe a technique that leverages a pre-tied knotted high-tension suture construct to allow for a re-tensionable quadriceps repair.

Bilateral Quadriceps Tendon Rupture in a Healthy Individual Following a Motor Vehicle Accident: A Case Report

Bilateral quadriceps tendon rupture (QTR) is a rare injury that typically affects middle-aged men presenting underlying medical conditions, while only a few cases have been reported in healthy individuals. The gold standard treatment of such injuries is prompt surgical repair, followed by postoperative immobilization and physiotherapy. We present the case of a 51-year-old previously healthy man who experienced bilateral, simultaneous, and complete QTR following a high-velocity motor vehicle accident. Physical examination revealed bilateral extensor mechanism disruption and palpable defects at the superior poles of the patellae. MRI confirmed the diagnosis, and the patient underwent surgical repair using three anchor sutures on each side. Postoperative management involved a brief period of immobilization followed by progressive passive motion exercises and protected weight bearing. At a six-month follow-up, the patient had excellent functional outcomes and was satisfied with the treatment.

Transosseous Repair With Nice Knot Augmentation Versus Knotless Suture Anchor Repair With Suture Tape for Quadriceps Tendon Rupture: A Cadaveric Study

Quadriceps tendon rupture is typically repaired using either transosseous tunnels or suture anchors. Recent literature has suggested that suture anchor repair is biomechanically superior to the use of transosseous tunnels. Augmentation of the transosseous technique with Nice knots may result in improved biomechanical properties as compared with a suture anchor construct. To compare biomechanical properties of a novel transosseous quadriceps tendon repair technique with Nice knot augmentation to those of knotless suture anchor repair, an artificial quadriceps tendon rupture was created in 10 matched pairs of cadaveric knees (n=20). Each cadaver was subjected to biomechanical testing to calculate the average ultimate load to failure, repair site gapping after early and late cyclic loading, and stiffness. Transosseous repair augmented with Nice knots as compared with knotless suture anchor repair had greater load to failure (mean±SD, 1489.5±297.6 N vs 717.7±191.4 N, P<.001), decreased gapping after early and late cyclic loading (cycles 1-20: mean±SD, 0.59±0.4 mm vs 2.1±1.2 mm, P=.008; cycles 21-250: mean±SD, 1.2±0.7 mm vs 3.9±1.7 mm, P=.002), and greater construct stiffness (mean±SD, 80.7±15.7 N/mm vs 44.4±13.4 N/mm, P=.001). The transosseous quadriceps tendon repair technique with Nice knot augmentation is biomechanically better than knotless suture anchor repair with regard to ultimate load to failure, gap formation after cyclic loading, and construct stiffness in cadaveric specimens. [Orthopedics. 202x;4x(x):xx-xx.].

Suture Anchor-Based Quadriceps Tendon Repair May Result in Improved Patient-Reported Outcomes but Similar Failure Rates Compared to the Transosseous Tunnel Technique

PURPOSE

The purpose of this study was to compare failure rates and patient-reported outcomes between transosseus (TO) suture and suture anchor (SA) quadriceps tendon repairs.

METHODS

Following institutional review board approval, patients who underwent primary repair for quadriceps tendon rupture with TO or SA techniques between January 2009 and August 2018 were identified from an institutional database and retrospectively reviewed. Patients were contacted for satisfaction (1-10 scale), current function (0-100 scale), failure (retear), and revision surgeries; International Knee Documentation Committee (IKDC) score and Knee Injury and Osteoarthritis Outcomes Score (KOOS) were also collected to achieve a minimum of 2-year follow-up.

RESULTS

Sixty-four patients (34 SA, 30 TO) were available by phone or e-mail at a mean of 4.81 ± 2.60 years postoperatively. There were 10 failures, for an overall failure rate of 15.6%. Failure incidence did not significantly differ between treatment groups (P = .83). Twenty-seven patients (47% of nonfailed patients) had completed patient-reported outcomes. The SA group reported higher subjective function (SA: 90 [85-100] vs TO: 85 [60-93], 95% CI of difference: -19.9 to -2.1 × 10^-5, P = .042), final IKDC (79.6 [50.0-93.6] vs 62.1 [44.3-65.5], 95% CI of difference: -33.0 to -0.48, P = .048), KOOS Pain (97.2 [84.7-97.2] vs 73.6 [50.7-88.2], 95% CI of difference: -36.1 to -3.6 × 10^-5, P = .037), Quality of Life (81.3 [56.3-93.8] vs 50.0 [23.4-56.3], 95% CI of difference: -50.0 to -6.2, P = .026), and Sport (75.0 [52.5-90.0] vs 47.5 [31.3-67.5], 95% CI of the difference: -45.0 to -4.1 × 10^-5, P = .048).

CONCLUSIONS

There is no significant difference in failure rate between transosseus and suture anchor repairs for quadriceps tendon ruptures (P = .83). Most failures occur secondary to a traumatic reinjury within the first year postoperatively. Despite the lack of difference in failure rates, at final follow-up, patients who undergo suture anchor repair may report significantly greater subjective function and final IKDC, KOOS Pain, Quality of Life, and Sport scores.

LEVEL OF EVIDENCE

III, retrospective cohort study.

Suture Bridge Transosseous Quadriceps Tendon Repair for Spontaneous Quadriceps Tendon Rupture in Patients With End-Stage Renal Disease

End-stage renal disease with spontaneous quadriceps tendon rupture (QTR) is a specific condition that differs from classic QTR. The tissue quality of the quadriceps tendon (QT), the rupture site, the mechanism of injury, and the pathophysiology of the rupture mechanism all have an effect on conventional QT repair procedures, with a higher likelihood of rerupture or failed repair construction. We believe that our technique provides repair-site stability, strong repair construction, increased contact surface healing, and a reduced chance of rerupture after QT repair. Furthermore, in most patients who have end-stage renal disease with QTR, misdiagnosis and/or underestimation occurs, resulting in proximal retraction of the QT and poor results; however, this technique can be performed with alternative procedures such as augmentation or QT lengthening. The suture bridge transosseous QT repair technique relies on biomechanics knowledge for better stability. Suture bridge repair concept can achieve better healing of all layers of the QT until returning to normal activity with no disability and an improved quality of life.

Primary Quadriceps Tendon Suture Anchor Repair: Case Presentation and Surgical Technique

This case presentation described a technique for repairing an acute quadriceps tendon rupture with suture anchors. The patient was a 51-year-old man who sustained an acute quadriceps tendon rupture after a fall. We used a midline incision over the quadriceps tendon and muscle. The tendon was found to be completely avulsed from the superior border of the patella. Three suture anchors were used to re-approximate the quadriceps tendon to the patella and additional sutures were used to repair the medial and lateral patellar retinacula. The patient had excellent range of motion at his 6-week follow-up appointment after the procedure.

Do Patellar Tendon Repairs Have Better Outcomes than Quadriceps Tendon Repairs? A Prospective Cohort Analysis

Patellar tendon (PT) and quadriceps tendon (QT) ruptures represent significant injuries and warrant surgical intervention in most patients. Outcome data are predominantly retrospective analyses with low sample sizes. There are also minimal data comparing QT and PT repairs and the variables impacting patient outcomes. The level of evidence of the study is level II (prognosis). From the prospective OME cohort, 189 PT or QT repairs were performed between February 2015 and October 2019. Of these, 178 were successfully enrolled (94.2%) with 1-year follow-up on 141 (79.2%). Baseline demographic data included age, sex, race, BMI, years of education, smoking status, and baseline VR-12 MCS score. Surgical and follow-up data included surgeon volume, fixation technique, baseline, and 1-year Knee Injury and Osteoarthritis Outcome Score-Pain (KOOS-Pain), Knee Injury and Osteoarthritis Outcome Score-Physical Function (KOOS-PS), and 1-year Patient Acceptable Symptom State (PASS) scores and complications. Multivariable regression analysis was utilized to identify prognosis and significant risk factors for outcomes-specifically, whether KOOS-Pain or KOOS-PS were different between QT versus PT repairs. There were 59 patients in the PT cohort and 82 patients in QT cohort. Baseline demographic data demonstrated that PT cohort was younger (45.1 vs. 59.5 years, p <0.001), included significantly fewer patients of White race (51.7 vs. 80.0%, p = 0.001), lesser number of years of education (13.9 vs. 15.2 years, p = 0.020), a higher percentage of "high" surgeon volume (72.9% vs. 43.9%, p = 0.001) and 25.4% of PT repairs had supplemental fixation (QT had zero, p <0.001). Multivariable analysis identified gender (female-worse, p = 0.001), years of education (higher-better, p = 0.02), and baseline KOOS-Pain score (higher-better, p <0.001) as the risk factors that significantly predicted KOOS-Pain score. The risk factors that significantly predicted KOOS-PS were gender (female worse, p = 0.033), race (non-White-worse, p <0.001), baseline VR-12 MCS score (higher-better, p <0.001), and baseline KOOS-PS score (higher better, p = 0.029). KOOS-Pain and KOOS-PS scores improved after both QT and PT repairs. Patient reported pain and function at 1 year were similar between PT and QT repairs after adjusting for known risk factors. Multivariable analysis identified female gender and low baseline KOOS scores as predictors for worse outcomes.

Smaller Gap Formation With Suture Anchor Fixation Than Traditional Transpatellar Sutures in Patella and Quadriceps Tendon Rupture: A Systematic Review

PURPOSE

The purpose of this study is to compare the biomechanical properties between traditional transosseous tunnel and suture anchor technique repair for extensor mechanism ruptures and assess for differences in the mechanism of failure of both techniques.

METHODS

A multi-database search (PubMed, EMBASE, and Medline) was performed according to PRISMA guidelines on November 14, 2021. All articles comparing biomechanical properties of transpatellar and suture anchor technique for extensor mechanism ruptures were included. Abstracts, reviews, case reports, studies without biomechanical analysis, conference proceedings, and non-English language studies were excluded. Outcomes pursued included gap formation, load to failure, and mechanism of failure. Relevant data from studies meeting inclusion criteria were extracted and analyzed. Study methodology was assessed using the Methodological Index for Non-Randomized Studies score.

RESULTS

A total of 212 knees were biomechanically assessed, including 98 patella and 114 quadricep tendon ruptures. Five patellar tendon studies were included, and all of them reported significantly smaller gap formation in suture anchor group. Gap formation for suture anchors ranged from .9 mm to 4.1 mm, while that of transpatellar group ranged from 2.9 mm to 10.3 mm. One study reported a significantly higher load to failure in the suture anchor group, while the remaining four studies reported no significant difference. Load to failure for suture anchor ranged from 259 N to 779 N, while that of the transpatellar group ranged from 287 N to 763 N. The most common mechanism of failure was anchor pullout in suture anchor and knot failure in the transpatellar group. Five quadriceps tendon studies were included, and three studies reported statistically significant smaller gap formation in the suture anchor group. Gap formation for suture anchor ranged from 1.5 mm to 5.0 mm, while that of transpatellar group ranged from 3.1 mm to 33.3 mm. Two studies reported a significantly higher load to failure in the suture anchor group, while one study reported a higher load to failure in the transpatellar repair group. Load to failure for suture anchor ranged from 286 N to 740 N, while that of transpatellar group ranged from 251 N to 691 N. The most common mechanism of failure was suture failure in the suture anchor and knot failure in the transpatellar group.

CONCLUSION

Suture anchor fixation displays a better biomechanical profile than traditional transpatellar techniques in terms of smaller gap formations in the repair of both patella and quadriceps tendon injuries. Anchor pullout in suture anchor fixation was present mainly with the use of titanium anchors.

CLINICAL RELEVANCE

These findings above may result in better retention of tendon approximation in patella and quadriceps tendon fixation postoperatively, which may result in earlier recovery. Further randomized controlled clinical trials to compare these techniques are required.

Extensor mechanism ruptures

Native patellar tendon injuries are seen in younger patients compared to quadriceps tendon ruptures.

Up to a third of the patients may have local (antecedent tendinopathy and cortisone injections) or systemic risk factors (obesity, diabetes, hyperparathyroidism, chronic renal failure, fluoroquinolone or statin use) of injury, these are more frequent in bilateral disruptions.

Complete extensor mechanism disruptions should be repaired surgically. Although isolated primary repair has been reported to have good outcomes in younger patients with acute tears and good tendon quality, augmentation of the repair with autograft, allograft or synthetic material should be considered in patients with poor tendon quality, chronic tears or tendon defects.

High rates of return to work/sports have been reported in native patellar and quadriceps tendon tears, with re-rupture rates <5%.

Extensor mechanism disruptions in patients with a total knee arthroplasty are challenging due to older age, systemic co-morbidities and poor local conditions, resulting in inferior outcomes compared to native extensor mechanism injuries. Some form of augmentation with autograft, allograft or synthetics is advisable in all cases. Salvage procedures such as whole extensor mechanism allografts provide acceptable outcomes in multiply operated knees with extensive bone and soft tissue deficits.

Transosseous tunnels versus suture anchors for the repair of acute quadriceps and patellar tendon ruptures: A systematic review and meta-analysis of biomechanical studies

BACKGROUND

Multiple techniques have been developed for the repair of acute quadriceps and patellar tendon ruptures with the goal of optimizing clinical outcomes while minimizing complications and costs. The purpose of this study was to evaluate the biomechanical properties of transosseous tunnels and suture anchors for the repair of quadriceps and patellar tendon ruptures.

METHODS

A systematic review of the PubMed and Embase databases was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using specific search terms and eligibility criteria. Meta-analysis was performed by fixed-effects models for studies of low heterogeneity (I² <25%) and random-effects models for studies of moderate to high heterogeneity (I² ≥25%).

RESULTS

A total of 392 studies were identified from the initial literature search with 7 studies meeting the eligibility criteria for quadriceps tendon repair and 8 studies meeting the eligibility criteria for patellar tendon repair. Based on the random-effects model for total gap formation and load to failure for quadriceps tendon repair, the mean difference was 8.88 mm (95% CI, -8.31 mm to 26.06 mm; p = 0.31) in favor of a larger gap with transosseous tunnels and -117.25N (95%CI, -242.73N to 8.23N; p = 0.07) in favor of a larger load to failure with suture anchors. A similar analysis for patellar tendon repair demonstrated a mean difference of 2.86 mm (95% CI, 1.08 mm to 4.64 mm; p = 0.002) in favor of a larger gap with transosseous tunnels and -56.34N (95% CI, -226.75 to 114.07N; p = 0.52) in favor of a larger load to failure with suture anchor repair.

CONCLUSIONS

Transosseous tunnels are biomechanically similar to suture anchors for quadriceps tendon repair. Patellar tendon repair may benefit from reduced gap formation after cycling with suture anchor repair, but the load to failure for both techniques is biomechanically similar. Additional studies are necessary to evaluate these and alternative repair techniques.

LEVEL OF EVIDENCE

Systematic review and meta-analysis of biomechanical studies, Level V.

Early, Bilateral Re-Rupture of Quadriceps Tendon After Previous Bone-Anchor Repair for Simultaneous, Low-Energy, Bilateral Quadriceps Rupture: A Case Report and Literature Review

Patient: Male, 42-year-old

Final Diagnosis: Bilateral quadriceps tendon re-rupture

Symptoms: Disability • pain

Medication: —

Clinical Procedure: —

Specialty: Orthopedics and Traumatology

Biomechanical Testing of Suture Anchor Versus Transosseous Tunnel Technique for Quadriceps Tendon Repair Yields Similar Outcomes: A Systematic Review

PURPOSE

To systematically review the literature to evaluate the biomechanical properties of the suture anchor (SA) versus transosseous tunnel (TO) techniques for quadriceps tendon (QT) repair.

METHODS

A systematic review was performed by searching PubMed, the Cochrane Library, and Embase using PRISMA guidelines to identify studies that evaluated the biomechanical properties of SA and TO techniques for repair of a ruptured QT. The search phrase used was "quadriceps tendon repair biomechanics". Evaluated properties included ultimate load to failure (N), displacement (mm), stiffness (N/mm), and mode of failure.

RESULTS

Five studies met inclusion criteria, including a total of 72 specimens undergoing QT repair via the SA technique and 42 via the TO technique. Three of 4 studies found QTs repaired with SA to have significantly less elongation upon initial cyclic loading when compared to QTs repaired with the TO technique (P < .05). Three of 5 studies found QTs repaired with SA to have significantly less elongation upon final cyclic loading when compared to QTs repaired with the TO technique (P < .05). The pooled analysis from 4 studies reporting on initial displacement showed a statistically significant difference in favor of the SA group compared to the TO group (P = .03). The pooled analysis from studies reporting on secondary displacement and ultimate load to failure showed no significant difference between the SA and TO groups (P > .05). The most common mode of failure in both groups was suture slippage.

CONCLUSION

On the basis of the included cadaveric studies, QTs repaired via the SA technique have less initial displacement upon cyclic testing when compared to QTs repaired via the TO technique. However, final displacement and ultimate load to failure outcomes did not reveal differences between the two fixation strategies. Knot slippage remains a common failure method for both strategies.