Pie-crusting Technique Research Articles

Primary Results of Medial Epicondylar Osteotomy in Patients with Severe Bilateral Varus Knee Candidate for Total Knee Replacement

Total knee arthroplasty is a challenging task in patients with severe varus deformity. In most of these patients, an extensive medial release is needed that may lead to instability. Medial epicondylar osteotomy may be a better substitute for complete medial collateral release. Fourteen patients with bilateral knee osteoarthritis and severe varus deformity were enrolled in this study. In one side, the patients underwent medial epicondylar osteotomy for mediolateral imbalance if the only option was superficial medial collateral ligament (MCL) release. In contralateral side, the extensive medial release was performed and MCL was released either by pie-crusting technique or by subperiosteally release. The results of the two sides were compared. Patients were followed up for 12 months after the operation. Physical examination, clinical questionnaires, and radiography findings were recorded. Union of the osteotomies fragment and complications was evaluated. The mean varus angle before surgery was 21.6 ± 4.7 degrees, which was corrected to 8.6 ± 2.9 degrees after operation with an extensive medial release. The mean varus angle of contralateral side was 22.6 ± 1.7 degrees, which was corrected to 7.5 ± 2.3 degrees following medial femoral epicondyle osteotomy. There was no significant difference in varus correction (p = 0.1). Medial joint line opening in valgus stress test was 2.7 ± 0.4 mm in the osteotomized side and 3.5 ± 0.9 mm in contralateral side. Mean range of motion for the osteotomized side was 97.8 ± 4.3 degrees and 100.7 ± 2.7 degrees for contralateral side (p = 0.6). Nonunion occurred in a case in the osteotomized side and no medial instability was observed in medial release or osteotomies sides. No statistical difference was recorded based on clinical questionnaires (Oxford and WOMAC [Western Ontario and McMaster Universities Osteoarthritis Index] scores). Medial epicondylar osteotomy is a safe technique with the well-controlled medial extensive release in the patients with severe varus deformity during total knee arthroplasty.

Ultrasound-guided injection and the pie crust technique for the treatment of symptomatic bipartite patella.

This study aimed to investigate the results of a new treatment procedure (ultrasound-guided injection and the "pie crust" technique for lengthening of capsular tendon structures) for symptomatic bipartite patella. We retrospectively investigated patient outcomes following the treatment of symptomatic type III bipartite patella with our new technique. Fifteen knees in 14 boys (mean age, 13.0 ± 1.7years) were included. The procedure involved the injection of 1% lidocaine (2mL) and triamcinolone acetonide (5mg) between the patella and fragment. We then punctured 10 sites from one skin puncture to extend lateral capsular tendon structures. The patients were clinically assessed using the Victorian Institute of Sports Assessment (VISA) score before and 1week, 1month, and 3months after the procedure. Patients were also evaluated for complications. The average VISA score was 45.7 ± 4.7 before treatment, 70.6 ± 7.3 at 1week post-treatment, 84.4 ± 16.6 at 1month post-treatment, and 88.6 ± 18.3 at 3months post-treatment. The VISA score improvement from before the procedure to 1week after the procedure was significant (P < 0.01). There were no complications in any of the patients, who returned to sports at a mean of 4.2 ± 2.1weeks after the procedure. However, two patients (three knees) had poor results and could not return to action; thus, they underwent surgical treatment 4months after the ultrasonographic procedure. This novel method is a potential treatment option for the management of symptomatic bipartite patella in outpatient clinics.

Efficacy of Pie-Crusting Technique on Soft Tissues in Distal Tibia and Fibula Fractures

Distal tibia and fibula fractures are challenging injuries to treat as evidenced by the high rates of wound complications because of vulnerable soft tissue coverage. The aim of this study was to examine the effect on soft tissue complications of the pie-crusting technique when applied between 2 incisions in distal tibia and fibula fractures treated with open reduction and internal fixation. We reviewed 34 patients with distal tibia and fibula fractures treated between September 2014 and March 2017. The pie-crusting technique was performed during wound closure in 16 (47.06%) fractures (group 1) and classic wound closure was done in 18 (52.94%) fractures (group 2). The primary outcome was evaluated as the presence or absence of soft tissue complications such as superficial skin necrosis, deep skin necrosis, and deep infection. The mean age was 50.44 ± 13.51 (range 23 to 65) years in group 1 and 51.67 ± 14.49 (range 18 to 68) years in group 2. The mean follow-up time was 27.35 ± 9.02 (range 16 to 46) months. The mean surgery time after injury was 5.88 ± 3.5 (range 1 to 14) days in group 1 and 7.32 ± 4.25 (range 1 to 16) days in group 2. No soft tissue complications were seen in any patient in group 1. Five (27.77%) occurrences of superficial skin necrosis were observed in group 2. In 2 (11.11%) patients in group 2, deep necrosis and wound dehiscence occurred, and subsequent deep infection developed in 1 (5.55%) of these patients. The overall complication rate was higher in group 2 (p = .005). We believe that the pie-crusting technique is beneficial for wound closure in distal tibia and fibula fractures, because it reduces the tension of the skin and allows leakage of subcutaneous fluids.

Is percutaneous release of medial collateral ligament in medial compartment arthroscopy effective and reliable?

Aim: Arthroscopic visualization of the knee medial compartment can be challenging in tight knees and undesired chondral damage can occur during instrumentation in these cases. In order to achieve thorough examination of the medial meniscus and to avoid complications, pie crusting of medial collateral ligament (MCL) has been described, which provides opening of the medial joint space. However, concerns about over releasing and instability still remain. Moreover, the reliability and effectively of the pie-crusting technique has not been studied widely. In this study, we aimed to investigate the advantages and possible complications of percutaneous releasing of medial collateral ligament in medial compartment arthroscopy.Material and Methods: A total of 320 arthroscopic surgeries performed between 2014 and 2017 were reviewed retrospectively and 28 patients who underwent partial meniscectomy or repair by pie crust technique were included in the study. Mean follow up was 18 (6-40) months. Patients were evaluated clinically with the Lysholm score and Tegner score. Additionally, joint balance, valgus instability, pain or tenderness at the MCL region and numbness at the medial side of the joint was noted.Results: On physical examination, during valgus stress at 30° of knee flexion, only one patient showed Grade 1 laxity; however, no patients had subjective valgus laxity at the final follow-up. Furthermore, there was no pain or tenderness over the MCL and there were no signs of saphenous nerve or vein injury in any of the patients.Conclusion: Pie-crusting of the medial collateral ligament is an effective and reliable technique which provides enough space for visualization and instrumentation of the medial compartment, particularly in tight knees.Keywords: Pie crust; knee arthroscopy; knee mcl; percutaneous release.

The Pie-Crusting Technique for Capsular Management During Hip Arthroscopy

Hip arthroscopy is commonly performed for the treatment of femoroacetabular impingement and labral pathology. When arthroscopy for femoroacetabular impingement is performed, a capsulotomy is often utilized to maximize access and allow for improved visualization. When an extended interportal or T capsulotomy is performed, the iliofemoral ligament is transected, which can lead to micro or gross instability. The purpose of this Technical Note is to describe an alternative approach to the standard T capsulotomy using a pie crusting technique, which provides improved visualization of the femoral head–neck junction during the femoroplasty without the need for an extended capsulotomy and can also serve to create venting holes that prevent hematoma formation within the capsule.

Pie Crust Technique of the Deep Medial Collateral Ligament in Knee Arthroscopy: Ultrasound and Anatomic Study.

This article determines compartment opening of the medial articular space of the knee after pie crust (PC) technique of the medial collateral ligament (MCL) by ultrasound measurements and anatomic dissection. This is a cadaveric study of 12 specimens. Four anatomic references were marked on the skin. Distances between the femur and tibia in the internal compartment at 30 degrees of flexion were obtained with ultrasound measurements in four situations: with and without applying valgus force both prior and after the PC technique. Ultrasound measurements of the medial articular compartment were made twice and mean value was calculated. An anatomical dissection was performed and distances between the puncture marks and the infrapatellar branch of the saphenous nerve was measured. Lilliefors test of normality was applied and variables were expressed as mean and standard deviation (SD). Qualitative variables were expressed by absolute frequencies and percentages. Statistical significance was a two-tailed p-value of < 0.05. Prior to the PC technique, mean (SD) distance between the femur and tibia in the medial compartment were 14.2 (4.0) mm in basal conditions and 17.1 (3.7) mm when applying valgus force (p = 0.003). PC technique increased the mean (SD) distance by 1.9 (1.9) mm under basal conditions (p < 0.01) and 2.9 (1.6) mm when applying valgus force (p < 0.01). The infrapatellar branches of the saphenous nerve were not damaged and the mean (SD) distance between the punctures and the nerve was 9.0 (3.3) mm. The PC is a reproducible, safe, and measurable surgical technique that opens controllably the medial compartment. PC as described avoided damage to the nerve branches.

Variability in Elongation and Failure of the Medial Collateral Ligament After Pie-Crusting With 16- and 18-Gauge Needles

BackgroundIn knee arthroplasty with preoperative varus deformity, medial collateral ligament (MCL) release may be needed to achieve balance. Pie-crusting allows for controlled release, but questions remain regarding its ability to obtain predictable results. We compared 16- vs18-gauge needle punctures and determined the number of punctures required to (1) lengthen the MCL by 1 mm and (2) cause ligament failure. MethodsThirteen knees were dissected, leaving the femur and tibia with an isolated MCL, and randomly assigned to 16- or 18-gauge groups. Initial stiffness was assessed by cycling the ligament to 300 N for 5 cycles. The selected needle was used to make 10 punctures centered over the area of greatest tension. Cyclic testing was repeated after each set of punctures. Changes in MCL length and stiffness were measured. This process was repeated until failure. ResultsNo differences occurred between the 16- and 18-gauge groups in cross-sectional area, initial stiffness, number of punctures to lengthen the MCL by 1 mm, or number of punctures to failure. As the number of punctures increased, a linear increase in elongation and decrease in stiffness occurred. ConclusionNeedle size was not the influencing factor. Variability in number of punctures, regardless of needle size, to elongate or fail the MCL shows the difficulty in developing a reproducible pie-crusting technique. This suggests that a standard number of punctures do not achieve controlled MCL lengthening for all patients, but that the number of punctures needed can be calculated for an individual knee based on the initial elongation after 10 punctures.

Pie-crusting technique is effective and safe to release superficial medial collateral ligament for total knee arthroplasty

BackgroundPie-crusting technique is a damage-control soft tissue balance skill of total knee arthroplasty (TKA). The outcome of this technique to release lateral soft tissue is reasonable. A limited number of studies have focused on medial collateral ligament release with pie-crusting technique in the past years because of concerns about its efficacy and safety. MethodAll cases underwent superficial medial collateral ligament (SMCL) release with either pie-crusting technique or traditional technique (39 knees in each group) between January 1, 2014 and August 31, 2015. A comparison study between two techniques was performed; meanwhile, 23 patients (26 knees) in pie-crusting group were followed up. Data including knee function, radiographic result and complications were analysed. ResultsComparison study demonstrates that pie-crusting technique can achieve a comparable or even better effect of alignment correction. Data of follow-up patients are reasonable. The mean postoperative flexion contracture is 1.2 ± 3.6°. The mean postoperative motion arrange is 104.0 ± 14.4°. The mean postoperative hospital for special surgery knee score point is 82.0 ± 7.4 points. The mean postoperative femoral tibial angle is 172.4 ± 2.0°. The level of joint line elevates around 2.1 ± 1.9 mm. There are four knees that use brace after operation, and none of them present unstable knee. No severe complication has been reported, and most patients were satisfied with life quality. ConclusionsUsing pie-crusting technique to release SMCL for TKA is effective and safe. The translational potential of this articleAlthough pie-crusting technique has been used in TKA for years, it is seldom chosen to release medial collateral ligament, especially to release SMCL, which is a vital step of malalignment correction. This study aims to evaluate the efficacy and safety of this technique in total knee arthroplasty patients.

Complex joint reconstruction and joint transplantation with the FLOCSAT concept-planning and surgical implementation

Cartilage defects in adult patients are so far incurable. Fresh osteochondral allograft (OCA) transplantation is based on the insertion of mature, living, mechanically sound hyaline cartilage into an osteochondral defect where it undergoes osseointegration. Intact hyaline cartilage of OCA does not cause immune reactions in the recipient. Many reports show that small OCA have good osseointegration and show good long-term results. These observations have been incorporated into the development of the fresh large (> 10 cm2) osteochondral shell allograft transplantation (FLOCSAT) concept, which is based on the following principles: 1) the thickness of the osseous layer should be kept as thin as possible (target < 6-8 mm) so that the transplant remains stable and fixable. This results in reduced segments of vascularization, simplified ossification and reduced immunogenic bone volume. 2) The bone surface is processed and enlarged (oscillating saw: pie crust technique, drill holes) and areas of sclerosis are simultaneously broken off. 3) Cell reduction and washing out of the bony layer with a pulsatile jet lavage. 4) Prevention of impaction and dessication: cartilage with its living chondrocytes are very sensitive to mechanical contusion and dessication. When introducing the transplant, the tissue must therefore be continually moistened and the pressure acting on the cartilage must be controlled. 5) Stable fixation: extensive uniplanar osteochondral transplants cannot be inserted by the press-fit method; therefore, fixation is carried out with small implants. In this publication we demonstrate how severe and complex posttraumatic or degenerative delayed problems can be solved using FLOCSAT.

Effectiveness and Safety of Needle Medial Collateral Ligament Pie-Crusting in Total Knee Arthroplasty: A Cadaveric Study.

Medial collateral ligament (MCL) pie-crusting technique in total knee arthroplasty (TKA) is one of the methods of medial release. The effects and risks of blade pie-crusting have been reported in previous studies. However, only a few have reported the safety and efficacy of needle pie-crusting. In this cadaveric study, we quantitatively evaluated the amount of gap change by MCL needle pie-crusting. We investigated five knees of four fresh human cadavers and performed posterior-stabilized TKA. Only deep MCL release as the medial release was conducted. We punctured the MCL from the deep layer to the superficial layer using a 18 G needle in a 90-degree flexion position for 0, 10, 20, 50, 75, and 100 times. Medial and lateral gaps were measured accurately with a balancer at determined times in 0 and 90-degree flexion positions. Changes in medial and lateral gaps were not significant differences in flexion and extension position. However, in 90-degree flexion, medial gap changes were tended to be larger than lateral gap changes. A 0.6 mm additional medial release and a 0.2 mm additional lateral release were found per 10 times pie crust in flexion position (100 times, p: 0.08). However, large differences existed among the cases. Needle pie-crusting is safer than blade pie-crusting because of the small efficacy of one-time pie crust. MCL needle pie-crusting showed varied effects for each case. This result indicates the risk of relaxation of an unexpected gap. Caution should be taken when choosing between needle pie-crusting and blade pie-crusting.

Concurrent femoral and tibial osteotomies versus soft tissue balance in total knee arthroplasty: A technical case report

This case report outlines some of the challenges as well as limitations in correction of osteoarthritis of the knee in combination with extra-articular deformities,and provides a novel and straightforward surgical solution in overcoming these challenges. We describe the case of a 37-year-old male who suffered from advanced bilateral tri-compartmental knee arthritis due to untreated bloodstream-sourced osteomyelitis after birth. Radiographs and surgery confirmed extremely severe deformities. We performed two different surgical techniques in order to correct extra-articular deformities (one-stage approach of concurrent tibial and femoral osteotomy and total knee arthroplasty on one side, and soft tissue balancing with “pie-crusting technique” plus total knee arthroplasty on the other side), with description of subsequent results at 36-months follow-up.

Algorithmic pie-crusting of the medial collateral ligament guided by sensing technology affects the use of constrained inserts during total knee arthroplasty.

Intra-operative sensing technology is an alternative to standard techniques in total knee arthroplasty (TKA) for determining balance by providing quantitative analysis of loads and point of contact throughout a range of motion. We used intra-operative sensing (VERASENSE-OrthoSensor, Inc.) to examine pie-crusting release of the medial collateral ligament in knees with varus deformity (study group) in comparison to a control group where balance was obtained using a classic release technique and assessed using laminar spreaders, spacer blocks, manual stress, and a ruler. The surgery was performed by a single surgeon utilizing measured resection and posterior-stabilized, cemented implants. Seventy-five study TKAs were matched 1:3 with 225 control TKAs. Outcome variables included the use of a constrained insert, functional- and knee-specific Knee Society score (KSS) at six weeks, fourmonths, and one year post-operatively. Outcomes were analyzed in a multivariate model controlling for age, sex, BMI, and severity of deformity. The use of a constrained insert was significantly lower in the study group (5.3 vs. 13.8%; p = 0.049). The use of increased constraint was not significant between groups with increasing deformity. There was no difference in functional KSS and knee-specific KSS between groups at any follow-up interval. An algorithmic pie-crusting technique guided by intra-operative sensing is associated with decreased use of constrained inserts in TKA patients with a pre-operative varus deformity. This may cause a positive shift in value and cost savings.

Outside-In Deep Medial Collateral Ligament Release During Arthroscopic Medial Meniscus Surgery

Arthroscopic partial medial meniscectomy is a very common orthopaedic procedure performed for symptomatic, irreparable meniscus tears. It is usually associated with a very good outcome and minimal complications. In some patients with tight medial compartment, the posterior horn of the medial meniscus can be difficult to visualize, and access in this area with instruments may be challenging. To increase the opening of the medial compartment, after valgus-extension stress position of the knee, different techniques of deep medial collateral ligament release have been described. The outside-in pie-crusting technique shown in this technical note has documented effectiveness and good outcomes with minimal or no morbidity.

Piecrusting to Facilitate Skin Closure

Wound dehiscence and infection may arise when the skin around the foot or ankle is closed under tension after a surgical incision or trauma. Two cases where a piecrusting technique, using small transdermal incisions made in the surrounding skin similar to the holes in a pie crust, are presented and a literature review of the technique has been performed. The multiple small stab incisions perpendicular to the line of tension have enabled skin closure without tension and have healed with minimal scarring. Level V: Expert opinion.

A Novel Medial Soft Tissue Release Method for Varus Deformity during Total Knee Arthroplasty: Femoral Origin Release of the Medial Collateral Ligament.

IntroductionNumerous methods of medial soft tissue release for severe varus deformity during total knee arthroplasty (TKA) have been reported. These include tibial stripping of the superficial medial collateral ligament (MCL), pie-crusting technique, and medial epicondylar osteotomy. However, there are inherent disadvantages in these techniques. Authors hereby present a novel quantitative method: femoral origin release of the medial collateral ligament (FORM).Surgical TechniqueFor medial tightness remaining even after the release of the deep MCL and semimembranosus, the FORM is initiated with identification of the femoral insertion area of the MCL with the knee in flexion. Starting from the most posterior part of the femoral insertion, one third of the MCL femoral insertion is released from its attachment. If necessary, further sequential medial release is performed.Materials and MethodsSeventeen knees that underwent the FORM were evaluated for radiological and clinical outcomes.ResultsRegardless of the extent of the FORM, no knees showed residual valgus instability at 24 weeks after surgery.ConclusionsAs the FORM is performed in a stepwise manner, fine adjustment during medial release might be beneficial to prevent inadvertent over-release of the medial structures of the knee.

Medial collateral ligament lengthening by standardized pie-crusting technique: A cadaver study

IntroductionPie-crusting (PC) is a tissue expansion technique using multiple perforation to lengthen the medial collateral ligament (MCL), but has still to be codified. HypothesisStandardized MCL PC allows measured opening of the medial femorotibial (MFT) joint line, without risk of MCL tear. Material and methodThirty-one knees were dissected, with medial parapatellar arthrotomy and resection of the cruciate ligaments and menisci. The deep MCL bundle was sectioned, and the thick anterior bundle (AB) of the MCL was observed in each knee. Knees were randomly allocated between AB sparing (AB+; n=15) or sectioning (AB−; n=16). A graduated dynometric tensor applied constant 80N distraction on the MFT joint line. MCL PC used a 19-G needle at the joint line, with a horizontal series of perforations every 2mm over the width of the MCL. MFT compartment opening was measured after each PC series. ResultsMean MFT space after sectioning the cruciate ligaments was 5.52±0.37mm, increasing by 1.64±1.28mm with AB sectioning. Twenty-five perforations were made in the AB+ and 16 in the AB− group. Final mean joint-line increase was 0.18±0.18mm in AB+ and 3.16±2.70mm in AB−. There were no MCL tears. DiscussionMCL pie-crusting was reliable and reproducible, achieving progressive MFT joint-line lengthening to a mean 8.71±2.62mm when associated to sectioning of the cruciate ligaments and MCL AB. Type of studyCadaver. Level of evidenceIV.

Reduction Osteotomy vs Pie-Crust Technique as Possible Alternatives for Medial Release in Total Knee Arthroplasty and Compared in a Prospective Randomized Controlled Trial

BackgroundTo compare the gap change between the pie-crust technique and reduction osteotomy to determine their effects on flexion and extension gaps and their success rates in achieving ligament balancing during total knee arthroplasty. MethodsIn a prospective randomized controlled trial, 106 total knee arthroplasties were allocated to each group with 53 cases. If there was a narrow medial gap with an imbalance of ≥3 mm after the initial limited medial release, either reduction osteotomy or pie-crust technique was performed. The changes of extension and flexion medial gaps along with the success rate of mediolateral balancing were compared. ResultsThere was a significant difference in the change of medial gap in knee extension with mean changes of 3.5 ± 0.5 mm and 2.3 ± 0.8 mm in the reduction osteotomy and pie-crust groups, respectively (P < .001). For flexion gap, greater change was found in the pie-crust group compared with the reduction osteotomy group; the mean medial gap changes in knee flexion were 1.1 ± 0.5 mm and 2.3 ± 1.2 mm in the reduction osteotomy and pie-crust groups, respectively. The success rates were 90.6% and 67.9% in reduction osteotomy and pie-crust groups, respectively (P = .007). ConclusionAs an alternative medial release method, reduction osteotomy was more effective in extension gap balancing, and pie-crust technique was more effective in flexion gap balancing. The overall success rate of mediolateral ligament balancing was higher in the reduction osteotomy group than in the pie-crust group.

Selective Medial Release Technique Using the Pie-Crusting Method for Medial Tightness During Primary Total Knee Arthroplasty

BackgroundThe pie-crusting method is popular in releasing lateral tightness during primary total knee arthroplasty (TKA) but is not well described for medial release. We established a selective medial release technique using the pie-crusting technique and investigated the effectiveness and safety of the technique during primary TKA. MethodsWe retrospectively reviewed 729 primary TKAs with varus deformity between October 2009 and June 2012. Medial tightness in flexion was released by traditional subperiosteal stripping for the anterior portion of the medial collateral ligament (aMCL). Medial tightness in extension was released by the pie crusting for the tight fibers in the posterior portion of the MCL and/or posteromedial corner structures (pMCL/PMCS). Clinical outcomes were evaluated by Knee Society (KS) scores and the Western Ontario and McMaster Universities Osteoarthritis Index. Any complications, including late medial instability that may be related to our surgical technique, were carefully inspected. ResultsAmong the 729 knees, 170 (23.3%) required subperiosteal stripping for balancing in flexion only, 186 (25.5%) required the pie-crusting for balancing in extension only and 142 (19.5%) required subperiosteal stripping and the pie-crusting for balancing in flexion and extension. The KS knee score was improved from 52.5 to 83.4, KS function score from 58.2 to 91.9, and Western Ontario and McMaster Universities Osteoarthritis Index from 42.7 to 21.8 (P < .001, all). No specific complications related to our technique were identified. ConclusionsThe selective medial release technique appears to be an effective and safe method to obtain a balanced mediolateral gap in primary TKA.

The pie-crusting technique using a blade knife for medial collateral ligament release is unreliable in varus total knee arthroplasty.

Despite the documented clinical efficacy of the pie-crusting technique for medial collateral ligament (MCL) release in varus total knee arthroplasty, its quantitative effects on medial gaps and safety remain unclear. This study was undertaken to determine the efficacy (quantitative effect and consistency of the number of punctures) and the safety (frequency of early over-release) of the pie-crusting technique for MCL release. From ten pairs of cadaveric knees, one knee from each pair was randomly assigned to undergo pie crusting in extension (group E) or in flexion (group F). Pie crusting was performed in the superficial MCL using a blade until over-release occurred. After every puncture, the incremental medial gap increase was recorded, and the number of punctures required for 2- or 4-mm gap increases was assessed. In group E, the extension gap increased from 0.8 to 5.0 mm and the flexion gap increased from 0.8 to 3.0 mm. In group F, the extension gap increased from 1.0 to 3.0 mm and the flexion gap increased from 2.6 to 6.0 mm. However, the gap increments were inconsistent with those that followed the preceding blade punctures, and the number of punctures required to increase the gaps by 2 or 4 mm was variable. The number of punctures leading to over-release in group E and group F was 6 ± 1 and 3 ± 1 punctures, respectively. Overall, 70% of over-release occurred earlier than the average number of punctures leading to over-release. Pie crusting led to unpredictable gap increments and to frequent early over-release. Surgeons should decide carefully before using the pie-crusting technique for MCL release and should be cautious of performing throughout the procedure, especially when performing in a flexed knee. Therapeutic study, Level I.

Is the Pie-Crusting Technique Safe for MCL Release in Varus Deformity Correction in Total Knee Arthroplasty?

Established for lateral release in TKA, the pie-crusting technique has not been studied for the medial collateral ligament (MCL). In cadaveric knees the MCL was release with a pie-crusting technique in one and traditional technique in the contralateral knee. Along with a control group, each MCL was subjected to mechanical testing. The stiffness, force and stress required to cause ligament elongation were less in the pie-crusting group (p < 0.05) compared to the control group, but were not statistically different than the traditional group. The pie-crusting group demonstrated a characteristic "stair-step" failure mode at the joint line, whereas the traditional group failed elastically at the tibial insertion. MCL pie-crusting is likely technique dependent since failure occurs within the ligament itself and further study is warranted.