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Nonabsorbable Suture of a PCL Allograft Resulting in a Squeaking Knee After PCL Reconstruction

A Case Report

Amin, Omar A. MD1,a; Alzahrani, Khalid H. MD2; Basaqr, Abdulaziz A. MD2; Tayeb, Mazen M. MD2

Author Information
doi: 10.2106/JBJS.CC.21.00684
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  • Disclosures


A squeaking joint is an undesirable, yet possible, outcome of joint surgery. Although this complication is rare, it can have a remarkable impact on an individual's quality of life1. A squeaking joint is one of the complications after arthroplasty surgery that mainly arises when the surgeon uses a ceramic-on-ceramic bearing surface surgical approach1-4. Few studies have investigated postoperative squeaking in the native knee. This case report describes a patient with a squeaking knee that developed after posterior cruciate ligament (PCL) reconstruction surgery. The surgery was performed to diagnose and eliminate the squeaking sound.

The patient was informed that data concerning the case would be submitted for publication, and he provided consent.

Case Report

In 2019, a 35-year-old man had developed a twisting left knee injury after participating in a football match and presented to our clinic. After performing a physical examination and special knee tests, including a positive posterior drawer test and positive posterior sag sign, a PCL tear was confirmed by magnetic resonance imaging (MRI). The posterior drawer test was positive intraoperatively, while the patient was under general anesthesia. A flip cutter (an all-inside technique) and an allograft prepared with an ORTHOCORD suture were used for the procedure. Left knee arthroscopy revealed a complete PCL tear. PCL reconstruction with allografts of the femoral and tibial tunnels was 10 and 9.5 mm, respectively. To ensure the left knee was stable before closure, the knee was examined. The graft was fixed, and the posterior drawer test was negative. Moreover, the anterior cruciate ligament (ACL) and medial and lateral menisci were also intact.

Seven months after surgery, the patient presented to the outpatient clinic complaining of persistent left knee pain, moderate swelling, and a squeaking sound, which he reported was audible when performing an active range of motion. He denied recurrent knee instability; however, after completing all physical therapy sessions, the patient returned to his job and limited his exercise regimen because of the pain and the unpleasant squeaking sound in his knee. Therefore, his social activities were minimized because of the embarrassment caused by his knee sound. Because the patient had a normal body mass index, denied using tobacco cigarettes, and engaged in bodybuilding exercises 4 times per week, he was advised to increase physical therapy sessions along with using analgesics for pain relief. However, the recommended physiotherapy and analgesics did not lead to a reduction in the pain or squeaking sound.

During the physical examination, we observed the patient's knees during walking. He had a normal gait and moderate swelling over the left knee. No left knee muscular atrophy, redness, hotness, or deformity was noted. A positive posterior drawer test was observed; however, no posterior sag sign was noted, and all special knee tests were normal. Moreover, his active range of motion was 0° to 135°, with an audible squeaking sound between 30° and 90° of the active range of motion (Videos 1 and 2).

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For the standard x-ray, anterior-posterior and lateral views of the left knee were captured. The resulting images showed that button construct fixation on the femur and tibia was noted after PCL reconstruction. The knee joint alignment was normal. Left knee soft-tissue swelling with air locales (accepted postoperatively) and knee joint effusion were detected. No sign of fracture was observed (Figs. 1-A and 1-B).

Fig. 1-A:
Fig. 1-A Anterior-posterior view of button construct fixation on the femur and tibia (red arrows).
Fig. 1-B:
Fig. 1-B Lateral radiograph of the left knee showing button construct fixation on the femur and tibia (red arrows).

A left knee MRI was ordered and revealed that after surgery, the PCL graft had thickened and showed an increased signal yet seemed intact with no evidence of a retear. The ACL and medial and lateral collateral ligaments were intact. The posterior horn of the medial meniscus showed an intrasubstance signal that did not reach either articular surface. Fraying of the root of the posterior of the medial meniscus was also observed, whereas other meniscal structures were intact. The patellar tendon, quadriceps tendon, and extensor mechanism were normal. Mild joint effusion with no Baker cyst was noted. The surrounding muscle groups and neurovascular bundles were normal (Figs. 2-A and 2-B).

Fig. 2-A:
Fig. 2-A A left knee magnetic resonance imaging, sagittal T1-weighted view showing that the posterior cruciate ligament graft had thickened (red arrow).
Fig. 2-B:
Fig. 2-B A left knee magnetic resonance imaging, sagittal T2-weighted view showing that the graft appeared intact and with no evidence of retear (red arrow).

Unfortunately, all examinations and efforts at conservative management failed, and the squeaking knee sound did not subside. Therefore, left knee arthroscopy was recommended for diagnosis and debridement of the intra-articular interposed suture (Figs. 3-A and 3-B). Furthermore, chondromalacia of grade 1 was noted (Fig. 3-A). Two weeks after the surgery, the patient returned to our clinic and reported being completely satisfied. Moreover, the patient returned to our clinic on 2 more occasions (once every 6 months) for the regular follow-ups. He reported that his knee no longer squeaked and that consequently, his activity levels and social conditions had improved.

Fig. 3-A:
Fig. 3-A An intraoperative arthroscopic image of the left knee showing the intra-articular interposed suture with chondromalacia grade 1 (red arrow).
Fig. 3-B:
Fig. 3-B An intraoperative arthroscopic image of the left knee showing the remaining of the intra-articular ORTHOCORD suture (red arrow).


This case report analyzed the cause of a squeaking knee, a rare complication after native knee surgery. Social distress is the main report associated with a squeaking knee. The main complications after PCL reconstruction surgeries are laxity and/or loss of stability of the knee that underwent surgery because of graft failure, graft impingement (which causes limitations in flexion-extension motion), arthrofibrosis, and/or persistent pain5,6.

Knee squeaking is mainly reported as a postarthroplasty complication when using the ceramic-on-ceramic device. This case describes a patient who underwent postligamental reconstruction for a squeaking knee. However, only few studies have described the same issue. The knee squeak finding in our study corresponds to findings from studies by Zarah et al. and Jay et al1,7.

The complication of knee joint squeaking appeared after PCL reconstruction; however, in the case report by Zarah et al.1, this condition appeared after medial patellofemoral ligament reconstruction, whereas the case report by Jay et al.7 indicated that the squeaking appeared after ACL reconstruction.

Joint squeaking can be a source of considerable distress to a patient; furthermore, it cannot be diagnosed by physical or radiological examination. The unpleasant squeaking sound was only audible during active motion and was not heard at the examination either passively or under anesthesia. The sound was not reproducible during the passive range of motion because biomechanically, the sound requires a nonabsorbable compression suture between the femoral and tibial condyle1.

In summary, complications associated with a squeaking knee caused by nonabsorbable sutures do not cease on their own over time. The friction of a nonabsorbable suture on articular cartilage with active compression across the knee joints produces a distinguishable and identifiable squeaking sound in which the nonabsorbable suture cannot be accurately diagnosed by medical imaging, including x-ray and MRI. In our case, the patient's reports and concerns about his squeaking knee gave us the indication to intervene surgically. Therefore, our surgical intervention by arthroscopic debridement was the only solution to permanently resolve the squeaking noise. These findings suggest that surgeons need to be aware when using nonabsorbable sutures because these sutures may cause undesirable complications resulting in a compulsory surgical intervention.


1. Zarah J, Chaudhry ZS, Freedman KB, Marchetto P, Hammoud S. Knee squeaking secondary to intra-articular nonabsorbable suture: a report of 2 cases. Orthop J Sports Med. 2017;5(7):2325967117716386.
2. Jarrett CA, Ranawat AS, Bruzzone M, Blum YC, Rodriguez JA, Ranawat CS. The squeaking hip: a phenomenon of ceramic-on-ceramic total hip arthroplasty. J Bone Joint Surg Am. 2009;91(6):1344-9.
3. Mai K, Verioti C, Ezzet KA, Copp SN, Walker RH, Colwell CW. Incidence of ‘squeaking’ after ceramic-on-ceramic total hip arthroplasty. Clin Orthop Relat Res. 2010;468(2):413-7.
4. Kuriyama S, Ishikawa M, Nakamura S, Furu M, Ito H, Matsuda S. Noise generation with good range of motion but without femorotibial instability has small effect on patient satisfaction after total knee arthroplasty. J Arthroplasty. 2017;32(2):407-12.
5. Alcalá-Galiano A, Baeva M, Ismael M, Argüeso MJ. Imaging of posterior cruciate ligament (PCL) reconstruction: normal postsurgical appearance and complications. Skeletal Radiol. 2014;43(12):1659-68.
6. Marom N, Ruzbarsky JJ, Boyle C, Marx RG. Complications in posterior cruciate ligament injuries and related surgery. Sports Med Arthrosc Rev. 2020;28(1):30-3.
7. Moran J, Kahan JB, Gardner E. Correction of a squeaky knee after ACL reconstruction surgery: a case report. JBJS Case Connect. 2021;11(2):e20.

knee; squeaking joint; PCL reconstruction; complication

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