Authors: Luke V. Tollefson, Nathan J. Jacobson, Robert F. LaPrade
Categories: Technical Note
Source: Arthroscopy Techniques
Patellar tendinopathy is an overuse injury of the patella tendon common in jumping sports or activities. Degeneration of the patellar tendon fibers causes microtears in the tendon, leading to partial patellar tendon tears. If nonoperative treatment fails and the tears are mild, a debridement of the detached tissue with a patella tendon repair can help to reduce pain, promote healing, and improve function. However, if more than 50% of the patella tendon attachment to the inferior pole of the patella is detached, a debridement with a patellar tendon reconstruction is indicated to restore the strength of the patellar tendon. This reconstruction technique uses gracilis and semitendinosus autografts to surround and reconstruct the patellar tendon. Tunnels are drilled horizontally at the tibial tubercle and through the midpoint of the patella for graft passage. This technique can help to improve patient outcomes and reduce some of the risk of failure associated with performing only the debridement when significant partial patellar tendon tearing is present.
Patellar tendinopathy is an overuse injury of the patellar tendon involving degeneration of the fibers of the patellar tendon.^1^ This injury is not a complete tear of the patellar tendon, but rather partial tearing typically occurring in running, jumping, and kicking sports.^2^^,^^3^ The tearing occurs almost exclusively at the superior pole of the patella tendon and typically is located on the posterior or posteromedial aspect of the tendon.^2^ Nonoperative treatment is recommended prior to surgical intervention.^4^ Nonoperative treatments include physical therapy, especially eccentric and isometric exercises; injections; and strapping/taping.^3^^,^^4^ Surgical intervention is indicated when these conservative methods fail.^5^
Various surgical techniques have been described to treat patellar tendinopathy.5, 6, 7 Surgical treatment involves removing the portion of the patellar tendon that is degenerated or has detached from the patella and has reported positive outcomes.^8^^,^^9^ Surgical management can be performed open, open with arthroscopic assist, or fully arthroscopic.5, 6, 7 Techniques vary on whether an additional bony resection of the distal pole of the paella is performed as well.^5^ Including a patellar tendon reconstruction along with the patellar tendon debridement is indicated for highly active individuals with >50% detachment of the patella tendon to reinforce the degenerative patellar tendon to improve strength and outcomes. The patellar tendon reconstruction is based on a previously described hamstring autograft reconstruction technique for a patellar tendon stretch tear.^10^^,^^11^ We describe a concomitant patellar tendon reconstruction after the debridement of degenerated patellar tendon tissue.
A detailed video of the patellar tendon reconstruction technique is shown in Video 1. The step-by-step guide and surgical pearls are in Table 1.
Clinical patient evaluation for patellar tendinopathy should begin with obtaining a dedicated patient history and obtaining a pertinent physical examination. Patellar tendinopathy typically presents with anterior knee pain localized to the inferior pole of the patella. Pain is typically worse after activity but can be present during activity as well. Magnetic resonance imaging (MRI) should also be obtained to evaluate the patellar tendon attachment on the inferior pole of the patella (Fig 1).
Fig 1 Magnetic resonance imaging (MRI) depicting patellar tendinopathy of the inferior pole of the patella tendon after failure of conservative treatment. This MRI is depicting >50% (or grade 4) tearing of the posterior aspect of the patella tendon. Sagittal (left) and axial (right) views should both be assessed. Thickening of the patellar tendon (red circles) is a common sign of patellar tendinopathy. An MRI should be obtained to assess tissue quality and determine if surgical intervention is indicated. The MRI should be used for preoperative planning, but visualization and confirmation during surgery is key. While visualizing the patellar tendon during surgery, if <50% of the patella tendon is detached from the inferior pole of the patella, a repair should be performed. If >50% of the patella tendon is detached from the inferior pole of the patella, a reconstruction should be performed.
Several classification systems have been proposed, including a symptom-based classification system by Blazina et al.^12^ This system consists of 4 phase 1 is pain only after the activity, phase 2 is pain or discomfort during the activity that does not interfere with sports participation, phase 3 is pain both during and after participation that interferes with competition, and phase 4 is complete tendon disruption. Another classification system by Golman et al.^2^ is an imaging-based system in which the patella tendon is graded on axial MRI. In this system, grade 1 is no patellar tendon tearing, grade 2 is a tear thickness <25%, grade 3 is a tear thickness between 25% and 50%, and grade 4 is a tear thickness >50% (Fig 1). Both classification systems should be used in assessing a patient with patellar tendinopathy.
Regardless of the classification of the injury, nonoperative treatment should be performed before surgical intervention. This can include physical therapy, bracing, injections, or nonsteroidal anti-inflammatory drugs. If 6 months of nonoperative treatment does not improve patient symptoms, surgical treatment is indicated. The surgical treatment depends on the condition of the patellar tendon. If <50% of the patella tendon is detached, then the affected tissue should be debrided, and a patellar tendon repair is indicated. If >50% of the tissue is detached, then the affected tissue should be debrided, and a patellar tendon reconstruction is indicated.
The patient is placed in the supine position on the operating table. Following induction under general anesthesia, a bilateral knee examination is performed to validate clinical examination findings. A well-padded high thigh tourniquet is placed. Both legs are draped in a sterile manner, and the surgical leg is placed in a leg holder (Mizho OSI) and the nonsurgical leg into an abduction stirrup (Birkova Product LLC). For infection prophylaxis, the standard dose of perioperative cefazolin should be administered.
The surgical approach is performed with an incision that extends from superior to the patella to distal to the tibial tuberosity. A fine dissection is carried out along the extensor mechanism.
The debridement of the patellar tendinopathy is performed first. The central portion of the patellar tendon is split vertically. The tissue that is nonviable and detached from the patella is sharply excised (Fig 2). Evaluation of the patella tendon is performed during this step; if more than 50% of the patella tendon is detached, then proceed with reconstruction.
Fig 2 Patellar tendon open debridement of a left knee due to severe patellar tendinopathy. A vertical incision (gray arrow) in the center of the patellar tendon originating at the inferior pole of the patella (black line) is performed. The tissue quality of the patella tendon should be assessed at this point. For this patient, about 70% of the tissue in the deep central portion of the patellar tendon at the distal pole of the patella is detached and thickened. All the nonviable tissue is removed using a scalpel and a rongeur. This site will be closed at the end of the procedure.
Next, the location for the patellar tendon reconstruction tibial tubercle tunnel is identified, and the periosteum at both sites is elevated. An anterior cruciate ligament (ACL) tibial guide (Arthrex) is used to drill a beath pin horizontally across the tubercle (Fig 3). For skeletally immature patients, fluoroscopy should be used to verify the tibial tunnel is distal to the open physis. This is overreamed with a 4.5-mm EndoButton (Smith & Nephew) reamer, and a passing stitch is placed.
Fig 3 This figure depicts the anterior cruciate ligament tibial guide being used to mark and drill the tibial tubercle tunnel for a left knee patellar tendon reconstruction. A guide pin (white arrow points to exit site) will be drilled through the guide and will be overreamed with a 4.5-mm EndoButton to allow for graft passage. Prior to overreaming, the position of the guide pin should be checked to ensure it is in the proper location. A passing stitch will be placed through the tunnel and the longer of the 2 hamstring autografts will be passed from medial to lateral through this tunnel.
Graft harvest is performed by first dissecting down to expose the semitendinosus and gracilis tendons. An open hamstring harvester (Arthrex) is used to harvest both tendons. The gracilis is harvested first, followed by the semitendinosus (Fig 4). The tibial insertions of both tendons are left attached. A metal ruler is used to debride residual muscle from the tendons, and the ends are whipstitched with No. 2 nonabsorbable sutures.
Fig 4 This figure is depicting the harvest of the gracilis autograft (blue arrow) for use in a left knee patellar tendon reconstruction. The gracilis tendon is first identified and a large Cobb elevator is used to remove adhesions before harvest. The graft harvester should be pushed firmly but carefully to ensure maximum graft length. The graft is left attached at the tibial insertion. The same process is repeated for the semitendinosus graft. In this case, the gracilis autograft is longer and will be passed through the tibial tubercle tunnel to be used on the lateral side and the semitendinosus autograft will be used on the medial side (white arrow shows tunnel location for gracilis graft). A metal ruler is used to debride residual muscle from the autografts and the free ends are whipstitched with a No. 2 nonabsorbable suture.
The longer of the 2 hamstring autografts is passed from medial to lateral across the tibial tubercle tunnel (Fig 5). The shorter hamstring autograft is passed within the deep tissues proximally along the medial edge of the patellar tendon up to the distal portion of the patella. Next, a Q-Fix anchor (Smith & Nephew) is placed at the graft entry site of the tibial tubercle. This medial Q-Fix anchor secures both the hamstring autografts. Next, a second Q-Fix anchor is placed laterally at the graft exit site. This lateral Q-Fix only secures the longer hamstring autograft that is passed medial to lateral.
Fig 5 This figure is depicting the gracilis tendon autograft being pulled medially to laterally through the tibial tubercle tunnel for a left knee patellar tendon reconstruction. When performing this surgery, the gracilis (blue arrow) and semitendinosus (black arrow) tendons are harvested to be used as the patella tendon reconstruction grafts. Both are left attached at the tibia and the longer of the 2 grafts should be used for this first pass. The gracilis graft is pulled fully through the tunnel. The gracilis and semitendinosus autografts are then secured at the medial tunnel exit site with a Q-Fix anchor. The gracilis autograft is also secured laterally at the tunnel entry site with a second Q-Fix anchor.
Next, a spinal needle is placed to mark the superior pole of the patella, and the patella length is measured. The midpoint of the patella is identified, and the ACL tibial guide is again used to drill a guide pin horizontally from lateral to medial (Fig 6). This is overreamed with a 4.5-mm EndoButton reamer.
Fig 6 This figure depicts the ACL tibial guide being used to mark and drill the patellar tunnel for a left knee patellar tendon reconstruction. This tunnel is located at the midpoint of the patella and should be measured to ensure proper placement. A guide pin will be drilled through this guide (white arrow depicts exit site), and it will be overreamed with a 4.5-mm EndoButton reamer for graft passage. The gracilis graft (blue arrow) will be routed first from lateral to medial through the tunnel. The semitendinosus graft (black arrow) will be routed second from medial to lateral through the same tunnel. Both grafts are pulled through the tunnel in their respective directions using a Hewson suture passer.
Both hamstring autografts are then passed deep to the fascia along the medial and lateral edges of the patellar tendon. The longer hamstring autograft is passed along the lateral edge of the patellar tendon and then from lateral to medial through the patellar tunnel (Fig 7). The shorter hamstring autograft is passed along the medial edge of the patellar tendon and then from medial to lateral through the patella tunnel (Fig 8). Both are passed through the bone tunnels using a Hewson suture passer (Smith & Nephew).
Fig 7 This figure is depicting the gracilis graft (blue arrow) being pulled through the patellar tunnel for a patellar tendon reconstruction of a left knee. This graft had previously been routed medially to laterally through the tibial tubercle tunnel, passed proximally underneath the superficial tissues to the patellar tunnel entry site, and then passed laterally to medially through the patellar tunnel. The semitendinosus graft (black arrow) can also be seen in this figure; it will be passed through the same patellar tunnel but instead routed medially to laterally. Once both grafts are pulled through the patellar tunnel, they will be sutured together at both the tunnel entry and exit sites. Care should be taken to ensure the grafts are properly tensioned and the patella height is positioned properly.
Fig 8 This figure is depicting the semitendinosus autograft (black arrow) being pulled through the patellar tunnel for a left knee patellar tendon reconstruction. This graft had previously been routed proximally from its tibial insertion, underneath the superficial tissues on the medial side of the patellar tendon, up to the patellar tunnel exit site. The semitendinosus graft is then passed medially to laterally through the patellar tunnel after the gracilis graft (blue arrow) is passed laterally to medially. The previously passed gracilis graft can also be seen. Both grafts are then secured to each other with suture at both the patellar tunnel entry and exit sites. Care should be taken to ensure the grafts are properly tensioned and the patella height is positioned properly.
Prior to final graft fixation, the rest of the surgery is now completed. Arthroscopy should be performed to evaluate the internal structures of the knee. When creating the arthroscopy portals, the grafts that have already been passed proximally should be palpated to ensure they are not amputated.
Finally, the graft fixation for the patellar tendon reconstruction is completed (Fig 9). The grafts are sutured to each other at the entry and exit tunnels of the patellar tunnel. During this step, it is critical to ensure the patella height is in the correct position and the grafts are taut during flexion of the knee. Once the grafts are tied to each other at the medial and lateral aspects of the patellar tunnel, they are passed distally along the medial and lateral edge of the original graft position. These extra portions are then sewn into the graft limbs that run proximally to reinforce the reconstruction. The site of the patellar tendon debridement is then closed with 0 Vicryl sutures. The tourniquet is then let down, and the deep and superficial tissues are closed with suture.
Fig 9 This figure depicts the final graft fixation for a left knee patellar tendon reconstruction. The 2 sutures that are whipstitched to the end of the grafts can be seen traveling distally. The suture on the left is secured to the gracilis graft (blue arrow), and the suture on the right is secured to the semitendinosus graft (black arrow). The medial exit of the tibial tunnel location is visualized with a blue arrow. The gracilis graft is passed medially to laterally through the tibial tubercle tunnel, and then it is routed proximally underneath superficial tissues to the entry of the patellar tunnel. It is then passed laterally to medially through the patellar tunnel and finally routed back distally along the semitendinosus graft. The semitendinosus graft is first routed proximally underneath the superficial tissues to the patellar tunnel exit site. It is then passed medially to laterally after the gracilis graft and finally routed back distally along the path of gracilis graft. Both grafts are secured at the medial exit of the tibial tunnel, and only the gracilis graft is secured at the lateral entry of the tibial tunnel. Both grafts are secured to each other at the entry and exit of the patellar tunnel and after they have been passed back down distally. Finally, both grafts are secured to each other after being routed distally along the original graft routes.
Physical therapy will begin the morning after surgery to work on quadriceps activation, edema control, and knee motion. Patients will be placed on low molecular weight heparin for deep vein thrombosis prophylaxis for 2 weeks and then transitioned to aspirin and TED hose until they initiate weightbearing. Range of motion will be restricted to 0 to 90 degrees for the first 2 weeks and progress as tolerated after that. Patients will be nonweightbearing on their surgical leg for 6 weeks. After 6 weeks, they will begin a weightbearing protocol, increasing weightbearing by 25% body weight per week.
This technique to surgically correct patellar tendinopathy is unique in that it includes a patellar tendon reconstruction in addition to the patellar tendon debridement. This surgery is indicated for highly active patients with significant partial patellar tendon tearing due to severe tendinopathy. Performing only a patellar tendon debridement or attempting a patellar tendon repair for a patient with significant partial tearing could result in poor functional outcomes and would most likely lead to failure when the patient returned to the same activities that caused the tendinopathy in the first place. Prior literature has reported positive outcomes separately for patellar tendinopathy debridement and patellar tendon reconstruction.^1^^,^5, 6, 7, 8, 9, 10^,^^13^ Advantages and disadvantages of this technique are listed in Table 2.
The patellar tendon debridement portion of this surgical technique is similar in technique to other previously reported literature. A clinical study by Gill et al.^8^ reported on clinical outcomes of 34 patients after a 2-year follow-up on patients with open debridement of the patellar tendon. Patients reported an average decrease of 5 points on the visual analog pain scale, 82% of patients were completely/mostly satisfied, and 78% would do the surgery again. A systematic review by Brockmeyer et al.^1^ reported that 87% of open patellar tendinosis surgical intervention surgeries are successful. The purpose of performing a patellar tendon debridement is to remove the damaged and inflamed tissue that would not heal on its own.
Patellar tendon reconstruction is indicated when a high percentage of tearing of the patellar tendon is present. A review by Gilmore et al.^13^ compared techniques used for complete patellar tendon tears via repair versus reconstruction across 41 studies and 503 patients. They reported that for chronic patellar tendon tears, reconstruction using autograft had the best functional outcomes and the lowest risk for complications. Patellar tendon reconstruction in addition to debridement in the setting of significant partial patellar tendon tearing provides the patients with improved functional outcomes and decreases the risk for potential complications.
The authors report the following potential conflicts of interest or sources of R.F.L. reports a relationship with Ossur that includes consulting or advisory and funding grants; Smith and Nephew that includes consulting or advisory, funding grants, and travel reimbursement; Responsive Arthroscopy that includes consulting or advisory; Arthroscopy Association of North America that includes funding grants; American Orthopaedic Society for Sports Medicine that includes funding grants; Foundation Medical, LLC that includes speaking and lecture fees; and a patent with royalties paid to Ossur. All other authors (L.V.T., N.J.J.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper*.* Full ICMJE author disclosure forms are available for this article online, as supplementary material.