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. 2016 Mar 30;8(1):51–59. doi: 10.1111/os.12220

Open Patellar Tendon Tenotomy and Debridement Combined with Suture‐bridging Double‐row Technique for Severe Patellar Tendinopathy

Bo Zhang 1, Tie‐bing Qu 1, Jiang Pan 1, Zhi‐wei Wang 1, Xiao‐dong Zhang 1, Shi‐xiang Ren 1, Liang Wen 1, Tong Chen 1, De‐si Ma 1, Yuan Lin 1,✉, Cheng‐Kung Cheng 2,3,✉
PMCID: PMC6584095  PMID: 27028381

Abstract

Objective

To create a new surgical procedure for chronic severe patellar tendinopathy and to evaluate its clinical efficacy.

Methods

In this retrospective study, the data of 12 patients with severe patellar tendinopathy in 14 knees who had undergone surgical treatment at Beijing Chao‐Yang Hospital between 1 March 2009 and 1 August 2013 were analyzed. Inclusion criteria included severe patellar tendinopathy (Phase III), conservative therapy for more than 6 months, American Society of Anesthesiology status Grade I–II, and body mass index <30. Patients with severe osteoporosis, complete tendon disruption (Phase IV) and those who were unable to cooperate were excluded. There were 8 men (10 knees) and 4 women (4 knees) cases. The patients’ ages ranged from 38 to 54 years (mean, 45.3 years). All surgeries had been performed by the same physician. Surgical treatment comprised incising open patellar midline tenotomy, complete debridement and suture‐bridging double‐row fixation. Isotonic and kinetic chain exercises were implemented after the second post‐operative week. A gradual increase to full weight‐bearing was allowed after the third post‐operative week and a gradual return to unrestricted use of the leg after the eighth post‐operative week. Preoperative and postoperative visual analogue scale (VAS) scores and Lysholm knee scores were obtained from the medical records or at recent postoperative follow‐up visits and the results compared using Student's two‐tailed paired t‐test.

Results

VAS scores decreased by a mean of 6.7 points (range, 1.1–7.8 points) during follow‐up (minimum duration 14 months; range, 14–44 months) and Lysholm scores increased from 55.7 ± 6.5 points to 90.4 ± 6.2 points. Three cases (4 knees) achieved excellent outcomes (≥95 points) and 9 cases (10 knees) good outcomes (range, 86–94 points). No intraoperative or postoperative complications occurred. There were significant differences between preoperative and postoperative VAS and Lysholm scores (P < 0.01).

Conclusions

All study patients achieved good or excellent outcomes. No patellar tendon rupture or suture fixation failure occurred during follow‐up. Suture‐bridging double‐row fixation is a simple and reliable method that not only improves patients’ clinical symptoms, but also restores knee joint function.

Keywords: Patellar tendinopathy, Surgery, Suture anchor, Treatment

Introduction

The term patellar tendinopathy (PT) refers to ultrastructural injury of the patellar tendon's terminal structure and is characterized pathologically by cartilage calcification or ossification, a thin tidemark and hyperplastic new bone. This condition was originally regards as an inflammatory tendinitis; however, it is now widely accepted as a degenerative disease of the patellar tendon. Thus, the term “tendinopathy” is more appropriate.1

Patellar tendinopathy, a relatively common clinical condition, may be caused by repeatedly using the knee extensor mechanism in explosive extension or eccentric flexion.2, 3, 4 It is characterized by pain, not only at the inferior pole of the patella, but also at the tibial attachment and the attachment of the tendon to the superior pole of the patella.5, 6, 7, 8, 9 Thus, the key physical finding in PT is tenderness at the inferior pole of the patella or in the main body of the tendon when the knee is fully extended and the quadriceps relaxed.10

The prevalence of PT is currently increasing, probably because of both increasing participation in sports and progress in diagnosis of this condition.11 Regarding the symptoms of PT, Blazina et al. described four phases, which are also applicable to other tendons: Phase I, pain only after activity; Phase II, pain/discomfort during activity that does not interfere with participation; Phase III, pain both during and after participation that interferes with competition; and Phase IV, complete tendon disruption.9

Early symptomatic PT (Phases I and II) is often treated conservatively, such treatment including non‐steroidal anti‐inflammatory drugs, rest, immobilization, eccentric exercise therapy, topical medications (such as steroids and triglycerides), ultrasound and radiation therapy; most of these modalities have shown some good results.12, 13, 14, 15 However, conservative treatment modalities aimed at modulating inflammation have had limited success in treating severe PT and also do not prevent painful conditions arising from overuse of tendons.16, 17, 18 In contrast, open surgical techniques and arthroscopic surgery make it possible to relieve the pain and restore function rapidly in patients who are unresponsive to nonoperative treatment. Such surgery aims to minimize tissue damage, mitigate compression at the attachment point and promote local blood circulation.19, 20, 21, 22, 23

Open surgical techniques comprise partial removal of the affected patellar tendon, opening of the peritendon, removal or drilling of the patellar pole, and so on.24, 25 Smillie, the first to report on the surgical treatment of patellar tendinopathy, recommended drilling multiple holes in the inferior patellar pole.26 Verheyden et al. resected the damaged portion of the patella and abraded the tendon insertion without performing a true osseous procedure; they recommended debridement of all of the damaged tendon tissue and reported an 87% rate of good and very good results in 29 patients, 7 of whom were volleyball players.27 Coleman et al. reviewed 25 surgical outcome studies and reported success rates ranging from 54% to 100% after open patellar tenotomy.16

There is currently controversy about whether arthroscopic or open techniques are better for the surgical treatment of severe PT. Both approaches are reportedly effective, the trend being toward better outcomes with arthroscopic techniques.28, 29, 30 Willberg et al. treated 15 patients with PT by arthroscopic shaving of the dorsal side of the proximal tendon and reported reduction of tendon pain, most patients going back to full tendon loading activity within 2 months of surgery.31 Ogon et al. used an arthroscopic technique to treat chronic PT and believed that the associated minimal surgical impact to the tendon promoted early and functional rehabilitation. Their technique is effective, easy to perform and safe to apply.32

Even though a number of groups have reported good results with open surgical techniques and arthroscopic surgery, neither of these approaches involves elimination of degenerated or calcified patellar tendon at the attachment point or resection of hyperplastic bone tissue. However, open tenotomy combined with debridement does address these problems and has been widely investigated in the treatment of severe PT which affects the point of attachment of the patellar tendon to the tibial tubercle.10 Surgeons can strip a section of the patellar tendon to remove degenerated patellar tendon tissue and proliferative osteophytes at the attachment point. However, if >40% of the tendon is stripped, the attachment point should be strengthened and fixed to avoid postoperative patellar tendon rupture.17 Currently, the surgical approach and fixation method remain controversial, few studies having addressed these issues.

Our study patients had undergone a procedure that comprised a midline patellar tendon incision, complete debridement and suture‐bridging double‐row fixation. We proposed this new surgical procedure for treating severe PT with the aim of increasing the tendon–bone contact area and stability, postulating that patients would resume normal activity earlier than after other forms of treatment; in this study we assessed the clinical efficacy of our procedure by analyzing its results.

Materials and Methods

Patients

We enrolled 12 patients with severe PT in 14 knees who had undergone surgical treatment at Beijing Chao‐Yang Hospital (Beijing, China) between 1 March 2009 and 1 August 2013. Inclusion criteria included severe PT (Phase III), conservative therapy for more than 6 months, American Society of Anesthesiology status Grade I–II and body mass index <30. Patients with severe osteoporosis, complete tendon disruption (Phase IV) and those who were unable to cooperate were excluded. There were 8 men (10 knees) and 4 women (4 knees) cases. The patients’ ages ranged from 38 to 54 years (mean age, 45.3 years). Most patients had lesions in the right knee (left:right = 4:10). None of the study patients were professional athletes; however, all were enthusiastic about running, skiing and mountain climbing. All patients were informed of this study, gave signed consent before surgery and informed consent for the retrospective analysis of their medical records and use of their data in this study. This study was approved by the Ethic Committee of Beijing Chao‐Yang Hospital, Capital Medical University (09‐S‐70). Surgery consisted of open midline patellar tenotomy, complete debridement and suture‐bridging double‐row fixation (Fig. 1).

Figure 1.

Figure 1

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Diagrammatic representation of surgical procedure. (A) A midline incision was made beginning at the patellar tendon–tibial tubercle attachment point and extending 6 cm proximally. (B) The patellar tendon was split and completely debrided to remove diseased tissue and two 4.5 mm twin‐tail anchors screwed into the holes in the middle of the stripped patellar tendon. (C) The fiberwires crossed longitudinally through the stripped patellar tendon through the cable and were then knotted. (D) Two white and two blue wires were crossed through the pin holes around the 4.5 mm anchors and then refixed on the each side of the tubercle attachment point.

All patients had undergone conservative therapy for more than 6 months, including oral non‐steroidal anti‐inflammatory analgesic drugs, rest, immobilization, physical therapy and steroid injections. All patients had knee joint pain, swelling and limited activity, with tenderness at the inferior pole of the patella and near the patellar tendon–tibial tubercle attachment point (Fig. 2). All patients underwent preoperative anteroposterior and lateral X‐ray and MRI examinations of the affected knee joint. Lateral X‐ray films revealed the presence of calcification or bone hyperplasia at the tibial tubercle in all 12 patients (14 knees) (Fig. 3), and MRI T1, T2 weighted images showed that the signals were enhanced around the patellar tendon attachment point (Fig. 4).

Figure 2.

Figure 2

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Clinical photograph showing swelling over the patellar tendon–tibial tubercle attachment point preoperatively; this had resolved completely at the latest follow‐up.

Figure 3.

Figure 3

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(A) Preoperative lateral X‐ray film showing the presence of osteophytes (arrow) at the patellar tendon attachment point. (B) Postoperative lateral X‐ray film showing that the osteophytes have been removed.

Figure 4.

Figure 4

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MRI images. (A) T1 weighted image showing the anatomical structure of the knee, signals of hyperplasia (arrow) are the same as of bone. (B) T2 weighted image showing that the signals are enhanced around the patellar tendon attachment point (arrow).

All surgeries were performed by the same physician. Relevant patient characteristics, including sex, age, laterality, duration of conservative therapy and operation time, were collected. Lysholm knee scores, which include eight items, namely limp, support, locking, instability, pain, swelling, stair climbing, and squatting, are one of the most important criteria for evaluating clinical outcomes. Preoperative and postoperative visual analogue scale (VAS) scores and Lysholm knee scores were obtained from the medical records or at the latest postoperative follow‐up. Postoperative complications were also recorded. Clinical assessment and data acquisition were performed by two physicians.

Surgical Methods

Patients were placed in a supine position under either general or spinal anesthesia. The affected leg was elevated and wrapped in a rubber bandage before pneumatic tourniquet inflation. A midline incision was made in the patellar tendon, beginning at the patellar tendon–tibial tubercle attachment point and extending 6 cm proximally. The patellar tendon was split through the midline incision and completely debrided to remove diseased tissue at the inferior pole of the patella and near the patellar tendon–tibial tubercle attachment point (Fig. 5). The patellar tendon was then partially dissected for less than 50% of its length (range, 30%–50%) and proliferative osteophytes exposed and removed using a rongeur (Fig. 6). The attachment point was trimmed smooth with a spherical burr (Fig. 7) and drilled at 5 mm intervals with a 2.5 mm Kirschner wire. The surgeon aimed to match the debridement range of the stripped tendon to the removal range of the osteophytes to accurately recover the patellar tendon length on both sides of the incision.

Figure 5.

Figure 5

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Incision. Photograph showing the midsection of the patellar tendon.

Figure 6.

Figure 6

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Stripping. Photograph showing the patellar tendon has been partially dissected from its attachment.

Figure 7.

Figure 7

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Debridement of the patella. Photograph showing complete debridement at the attachment point.

Following patellar tendon debridement and osteophyte removal, the patellar tendon attachment point was reconstructed using double‐row anchors. First, two parallel holes were drilled in the middle of the stripped patellar tendon, 2 cm above the patellar tendon attachment point. Two 4.5 mm twin‐tail anchors (Arthrex, Naples, FL, USA) were completely screwed into the holes, until the black line on the handle had reached the bone surface. The tail wires and tap rotary handle were then released, separating the handles from the anchors (Fig. 8). Each 4.5 mm anchor has four fiberwires, two blue in one group and two white in the other group. Fiber wires were crossed longitudinally through the stripped patellar tendon through the cable and then knotted (Fig. 9). Before knotting, the patients’ knees were fully extended to reduce tension on the patellar tendon. Next, another two 4.5 mm anchors (Arthrex) were drilled 1 cm below the patellar tendon attachment point; two white and two blue wires crossed through the pin holes around the 4.5 mm anchors at the proximal knotting site, after which the anchors were screwed until the black line on the handle reached the bone surface. After adjusting and maintaining the wire tension, the torsion bar was hammered onto the handle to fix the anchors and lock the tail wires. The second row of anchors was fixed using the same method. Finally, the ruptured tendon was closed using 0‐Vicryl suture (Fig. 10), the skin incision sutured, a sterile dressing and bandaged applied and the knee extended.

Figure 8.

Figure 8

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Anchoring. Photograph showing that two 4.5 mm anchors have been screwed into the stripped patellar tendon, 2 cm above the patellar tendon attachment point.

Figure 9.

Figure 9

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Double‐row fixation. Photograph showing that two sets of wires have been crossed through the stripped patellar tendon and knotted.

Figure 10.

Figure 10

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Wound suturing. (A) Photograph showing the eight tail wires have been divided into two groups and crossed for fixation. (B) The patellar tendon has been closed using 0‐Vicryl suture.

Postoperative Care

Patients were hospitalized and observed for 2 days postoperatively for wound hemorrhage, limb swelling and numbness, and to assess the tightness of the sterile dressing. Isotonic and kinetic chain exercises were implemented after the second post‐operative week. Gradual increase to full weight‐bearing was allowed after the third post‐operative week, when the knee effusion had subsided and the quadriceps had regained sufficient strength. Gradual return to unrestricted competition was allowed after the eighth post‐operative week. Patients were followed‐up at 1, 3, 6, and 12 months postoperatively, and then annually.

Statistical Analysis

Age, operation time and subjective outcome scores were analyzed to determine the mean and standard deviation of each set of data points. Preoperative and postoperative VAS and Lysholm scores were compared using a two‐tailed paired Student's t‐test. Alpha level was set as 0.05.

Results

Twelve patients (14 knees) with severe PT underwent open midline patellar tenotomy, complete debridement, and suture‐bridging double‐row fixation. The average duration of prior conservative therapy was 13.6 months (range, 6–28 months). The average operation time was 44.5 ± 6.8 minutes. No patients were lost to follow‐up, and the average follow‐up duration was 24.8 months (range, 14–44 months). According to the paired t‐test results, differences between preoperative and postoperative VAS (t = 3.92, P < 0.01) and Lysholm scores (t = 4.15, P < 0.01) were significant.

Postoperatively, the VAS scores decreased by a mean of 6.7 points (range, 1.1–7.8 points) and Lysholm scores improved from 55.7 ± 6.5 points to 90.4 ± 6.2 points. Three cases (4 knees) achieved excellent outcomes (≥95 points) and 9 (10 knees) good outcomes (range, 86–94 points). No intraoperative or postoperative complications occurred. All patients had achieved the maximum range of knee motion by the final follow‐up and no patellar tendon ruptures or suture/fixation failure occurred.

Discussion

The site of tendon and ligament attachments to the bone surface is defined as the tendon attachment zone. In 1959, La Cava first proposed the concept of PT,33 which has since been widely accepted.9 PT pain is confined to the anterior knee joint, particularly the inferior pole of the patella or the patellar tendon–tibial tubercle attachment point. This condition is also called jumper's knee because it is prevalent among running and jumping athletes, severe pain characteristically restricting normal activity.1, 34 Although no professional athletes were subjects in this study, all participating patients were enthusiastic about running, skiing and mountain climbing and all had anterior knee pain and limited motion, which affected their quality of life to varying degrees.

Currently, there is little evidence regarding the effectiveness of patellar tendon surgery. Surgical treatment is generally chosen for patients with severe PT in whom conservative treatment for 3 months has been ineffective.35, 36, 37 However, the choice of surgical approach is controversial. Popp et al. compared a variety of surgical approaches and found that the local drilling method achieved reliable results in patients with severe PT.19 Kaeding et al. stated that drilling the patella and patellar tendon attachment point increases regional blood flow and thus promotes patellar tendon healing.17 As arthroscopy has become more widely applied clinically, endoscopic debridement is now regarded as the optimal surgical approach because of the high patient satisfaction and fast recovery. Alaseirlis et al. performed arthroscopic surgery in 17 high‐level athletes in whom conservative treatment had been ineffective.11 They removed the patellar fat pad and degenerative tissue at the attachment point and obtained good therapeutic effects, with a mean postoperative Lysholm score of 92.5 points. This result is consistent with previous findings.38, 39, 40

Severe PT is often accompanied by extensive changes to the patellar tendon, comprising accumulation of calcified tissue and osteophyte formation at the patellar tendon–tibial tubercle attachment point. Complete debridement of the degenerated tissue and excision of osteophytes is required for surgical treatment to be successful. Although arthroscopic approaches and partial drilling decompression can decompress surrounding tissue, these methods do not involve completely stripping calcified or degenerated tendon tissue, nor do they permit removal of proliferative osteophytes, limiting their clinical efficacy. Conventional resection is considered the most effective treatment for severe PT.41, 42 In this study, we chose a midline incision, which enables complete removal of degenerated and calcified tissue within the patellar tendon and at the attachment point, as well as osteophyte resection. Ferretti et al. performed surgery on 32 patients with PT (38 knees) by open midline patellar tenotomy and removed degenerated tissue and osteophytes at the attachment point. Their good and excellent rate was 90% after 5 years’ follow‐up.43 Gill et al. retrospectively analyzed 34 patients (37 knees) who had a 2‐year follow‐up; treatment outcomes were unsatisfactory in only 6% of patients.35 All 12 patients (14 knees) in our study were followed up for an average of 2 years and, consistent with previous studies, postoperative VAS scores improved and knee function recovered.

Complete debridement depends largely on partial removal of the patellar tendon attachment point; however, the extent of removal remains controversial. No studies have reported complete removal of the patellar tendon. Kaeding et al. reported that removal of >40% at the attachment point increased the risk of patellar tendon rupture, and required stronger fixation.17 All patients’ patellar tendon attachment points were stripped by 30%–50% in our study and the fixation of the stripped patellar tendon strengthened to avoid patellar tendon rupture.

Determining how to repair the patellar tendon is a surgical challenge. The tendon attachment point can be reconstructed through fixation using anchors or auto‐graft transplantation; however, anchor fixation is preferred. The suture‐bridging double‐row fixation technique was originally used to repair rotator cuff injuries, and is now widely used in other locations, such as tibial spine avulsion fracture, displacement of the greater tuberosity of the humerus and Achilles tendon inflammation.44 Beitzel et al. re‐attached 18 cadaver Achilles tendons with suture anchors and found that double‐row repair increases contact area and achieves higher biomechanical stability (peak load, 433.9 ± 84.3 N).45 We therefore speculated that suture‐bridging double‐row fixation would achieve in situ fixation when reconstructing the patellar tendon after its partial removal and increase the contact area between the patellar tendon and the tibial tubercle, thereby reducing the risk of postoperative patellar tendon rupture and allowing weight‐bearing activity. We encountered no intraoperative or postoperative patellar tendon rupture, fixation failure, skin flap necrosis or other complications and the chief symptom of pain improved significantly, as did neurological function.

However, our study did have some limitations. First, we had a relatively small number of subjects because both parts of the patellar tendon are affected in few patients, reducing the reliability of our findings. Second, the duration of follow‐up was too brief to assess long‐term functional restoration and the incidence of recurrence. Third, patients were not randomly selected, which introduces a selection bias; Fourth, in terms of evidence‐based medicine, retrospective studies have inherent limitations. Thus, randomized, controlled trials are needed to address these limitations and compare the results of different surgical techniques, such as arthroscopic techniques or partial drilling decompression.

Conclusions

In conclusion, we found that open midline patellar tenotomy, complete debridement and suture‐bridging double‐row fixation is very effective in patients with severe PT and that this surgical technique fixes the stripped patellar tendon, relieves pain, improves function, maximizes the flexibility of the knee joint and promotes recovery. Additionally, this procedure is relatively simple, being associated with minimal trauma, short operation time and low complication rate. Although there are some limitations to this study, we believe that this surgical technique will be widely implemented in the clinic.

Disclosure: This study was funded by Health Industry Scientific Research projects of the National Health and Family Planning Commission (201302007).

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