Operative Techniques in Orthopaedic Surgery (4 Volume Set) 1st Edition

48. Repair of Acute and Chronic Patella Tendon Tears

Thomas M. DeBerardino and Brett D. Owens

DEFINITION

images Complete tears of the patella tendon are best classified into acute versus chronic.

images Partial tears often can be managed nonoperatively. The functional integrity of the extensor mechanism is the key to determining the need for surgical repair.

images This chapter focuses on the surgical treatment of complete tendon disruption.

ANATOMY

images The patella tendon is approximately 30 mm wide × 50 mm long, with a thickness of 5 to 7 mm.1

images The origin on the inferior pole of the patella is juxtaposed to the articular cartilage on the deep side and becomes confluent with the periosteum of the patella anteriorly.2

images The tibial insertion is narrower and invests the entirety of the tibial tubercle.

images The overlying peritenon is thought to be the cellular source for healing of tendon injuries.

PATHOGENESIS

images Tendon rupture usually is the result of underlying tendinosis.6

images There is some evidence of genetic predisposition to tendon rupture.

images Certain conditions predispose individuals to tendon rupture, including renal dialysis, chronic corticosteroid use, fluoroquinolone antibiotics, and corticosteroid use.

NATURAL HISTORY

images The natural history of an untreated patella tendon is complete extensor mechanism dysfunction.

images Untreated acute ruptures result in chronic lesions that are more difficult to manage surgically. These often require reconstructive procedures and have inferior functional results.

PATIENT HISTORY AND PHYSICAL FINDINGS

images Patients with acute tendon tears may report an audible “pop” or the sensation of their knee giving way.

images Patients with chronic injuries may report ambulatory difficulty and pain. These injuries often are treated with bracing before definitive evaluation.

images The loss of active knee extension is the key physical examination finding when evaluating for patella tendon rupture.

images Loss of tension in the patella tendon with the knee at 90 degrees of flexion and patella alta are indirect signs of rupture.

IMAGING AND OTHER DIAGNOSTIC STUDIES

images Plain radiographs may reveal patella alta, avulsion fractures, Osgood-Schlatter lesions, or other concomitant knee injuries.

images MRI scans may be helpful in determining the exact location of the rupture and evaluating concomitant intraarticular knee lesions.

DIFFERENTIAL DIAGNOSIS

images Quadriceps tendon rupture

images Patella fracture

images Tibial tubercle avulsion fracture

NONOPERATIVE MANAGEMENT

images Nonoperative management should be considered only for patients who are not surgical candidates because of medical comorbidities.

SURGICAL MANAGEMENT

images Although not considered to be a surgical emergency, prompt surgical management of acute patella tendon ruptures is recommended.

Preoperative Planning

images Repairs of chronic injuries often require allograft tissue availability and careful surgical planning.

images Significant patella alta may require proximal release in conjunction with the repair.

Positioning

images Supine postioning is recommended.

images Use of a tourniquet may preclude proper repair tensioning in chronic injuries.

images Prepping and draping of both lower extremities allows use of contralateral limb as a template for patella positioning.

Approach

images An anterior approach is used, regardless of the repair technique.

images A midline longitudinal incision is made over the patella tendon.

images The peritenon is incised longitudinally and dissected away from the underlying tendon.

TECHNIQUES

ACUTE REPAIR

Midsubstance

images  Grossly pathologic tendon tissue is aggressively débrided.

images  The full length of the patella tendon is exposed.

images  Two Krackow locking stitches are placed in each tendon stump with no. 2 or no. 5 Fiberwire (Arthrex, Inc., Naples FL; TECH FIG 1).

images  Any required retinacular repair stitches are placed with absorbable suture before the tendon repair.

images  The four proximal core sutures are tied to the four distal core sutures with the knee in full extension.

images  Integrity of the repair is evaluated by checking the maximal flexion possible prior to gap formation.

images  The peritenon is closed with absorbable suture.

Proximal Avulsion

images  Grossly pathologic tendon or bone is removed.

images  Exposure of the inferior pole of the patella is performed.

images  If the transosseous drill hole technique is preferred, superficial exposure of the superior pole of the patella is required.

images A smaller exposure is required for suture anchor technique.

images  Three suture anchors are placed in the inferior pole of the patella, equally spaced along the anatomic tendon footprint.

images We prefer the 5.0 Bio-Corkscrew FT Suture Anchor (Arthrex, Inc., Naples, FL) loaded with no. 2 Fiberwire (Arthrex, Inc., Naples, FL).

images

TECH FIG 1  Repair of acute midsubstance tear.

images  The suture is pulled through the anchor eyelet to produce long and short suture arms.

images The long suture arm is passed down and back up the tendon stump in a locking Krackow fashion (TECH FIG 2).

images  The tendon is manually reduced to the inferior pole of the patella, and the slack is taken out by the short arm of suture pulled through the eyelet.

images  Each suture pair is tied securely to complete the repair.

images  Repair integrity is evaluated by checking the maximal flexion possible before gap formation.

images  The peritenon is closed with absorbable suture.

Distal Avulsion

images  Grossly pathologic tendon or bone is removed.

images  The tibial tubercle is exposed.

images  Two suture anchors are placed in the tibial tubercle.

images We prefer the 5.0 Biocorkscrew FT Anchor loaded with no. 2 Fiberwire (Arthrex, Inc., Naples, FL).

images  The suture is pulled through the anchor eyelet to produce long and short suture arms. The long suture arm is passed up and back down the tendon stump in a locking Krackow fashion (TECH FIG 3).

images  The tendon is manually reduced to the tibial tubercle, and the slack is taken out by the short arm of suture pulled through the eyelet.

images  Each suture pair is tied securely to complete the repair.

images  Repair integrity is evaluated by checking maximal flexion possible before gap formation.

images  The peritenon is closed with absorbable suture.

images

TECH FIG 2  Repair of acute proximal avulsion.

images

TECH FIG 3  Repair of acute distal avulsion.

RECONSTRUCTION OF CHRONIC TEARS

images  Reconstruction of a chronic tear begins with aggressive débridement of dysplastic tissue.

images  Remaining tendon tissue is assessed for possible repair.

images  The tibial tubercle is exposed.

images  The Achilles allograft is prepared with 15-mm × 25-mm bone block.

images  A rectangular box is cut out of the tubercle with an oscillating microsurgical saw and osteotomes to receive the bone block.

images  The block is secured to the tubercle with 2-mm × 3.5-mm cortical screws (TECH FIG 4A).

images  Suture anchors are placed into the distal pole of the patella and onto the anterior cortex of the patella to secure allograft tendon to the patella (TECH FIG 4B).

images  The allograft tendon is draped over the quadriceps tendon and muscle fascia and secured with nonabsorbable suture.

images

TECH FIG 4  Chronic reconstruction with Achilles tendon allograft. The bone block is inlayed into the tibial tubercle and fixed with screws or staples. The soft tissue end of the graft is sutured into the patella with suture anchors and into the quadriceps with heavy nonabsorbable sutures. A. Lateral view. B. AP view.

AUGMENTATION PROCEDURES

images  After the repair has been completed, it is assessed for any need for augmentation.

images  The following materials can be used for augmentation. They are placed in a box-stitch fashion through drill holes in the patella and tubercle (TECH FIG 5A):

images Mersilene tape

images No. 5 Fiberwire

images No. 5 Ethibond

images Steel wire

images Cerclage cables

images Tibialis tendon allograft

images  A semitendinosus autograft also may be harvested proximally (while leaving its distal insertion intact) and passed through a drill hole in the patella and either through a drill hole in the tubercle or potted into the proximal tibia if the length is insufficient (TECH FIG 5B).

images

TECH FIG 5  Augmentation of the repair can be with a box-stitched suture (A) or a soft tissue graft (B).

images

POSTOPERATIVE CARE

images Weight bearing is allowed with the knee braced in extension.

images Early flexion allowances are determined intraoperatively by the quality of the tendon tissue and repair.

images Active-assisted range of motion is advanced as tolerated with the goal of 90 degrees of flexion by 4 to 6 weeks and full motion by 10 to 12 weeks after repair.

images Strengthening is initiated immediately with isometric quadriceps contractions and progressed to straight-leg raises at 6 weeks.

images Return to unrestricted activities is delayed until 6 months.

OUTCOMES

images Marder and Timmerman9 reported excellent results in 12 of 14 patients treated with acute repair without augmentation.

images Larson and Simonian7 reported excellent results (mean Lysholm score, 97.5) in four cases of acute repair augmented with autologous semitendinosus graft placed in a looped fashion.

images Lindy et al8 reported excellent results in 24 patients repaired acutely and augmented with Mersilene tape placed in a looped configuration.

images Fujikawa5 reported good results with a patella tendon repair augmented with a synthetic figure-8 weave performed on six patella tendon ruptures. They noted that the augmentation device allowed for early mobilization and good functional outcome.

images Two recent biomechanical studies show that an augmented repair is stronger than an unaugmented repair11 and that suture anchor repair is at least as strong as repair through drill holes.3

images Two cases of successful treatment of chronic patella tendon ruptures with Achilles allograft reconstruction have been reported.4,10

COMPLICATIONS

images Rerupture is the most worrisome complication.

images Infection is uncommon but devastating.

images Residual quadriceps weakness and extensor lag are more common with repairs of chronic injuries.

REFERENCES

1. Andrikoula S, Tokis A, Vasiliadis HS, et al. The extensor mechanism of the knee joint: an anatomical study. Knee Surg Sports Traumatol Arthrosc 2006;14:214–220.

2. Basso O, Johnson DP, Amis AA. The anatomy of the patellar tendon. Knee Surg Sports Traumatol Arthrosc 2001;9:2–5.

3. Bushnell BD, Byram IR, Weinhold PS, et al. The use of suture anchors in repair of the ruptured patellar tendon. Am J Sports Med 2006;34: 1492–1499.

4. Falconiero RP, Pallis MP. Chronic rupture of a patellar tendon: a technique for reconstruction with Achilles allograft. Arthroscopy 1996;12:623–626.

5. Fujikawa K, Ohtani T, Matsumoto H, et al. Reconstruction of the extensor apparatus of the knee with the Leeds-Keio ligament. J Bone Joint Surg Br 1994;76B:200–203.

6. Kannus P, Jozsa L. Histopathological changes preceding spontaneous rupture of a tendon. A controlled study of 891 patients. J Bone Joint Surg Am 1991;73A:1507–1525.

7. Larson RV, Simonian PT. Semitendinosus augmentation of acute patellar tendon repair with immediate mobilization. Am J Sports Med 1995;23:82–86.

8. Lindy PB, Boynton MD, Fadale PD. Repair of patellar tendon disruptions without hardware. J Orthop Trauma 1995;9:238–243.

9. Marder RA, Timmerman LA. Primary repair of patellar tendon rupture without augmentation. Am J Sports Med 1999;27:304–307.

10. McNally PD, Marcelli EA. Achilles allograft reconstruction of a chronic patellar tendon rupture. Arthroscopy 1998;14:340–344.

11. Ravalin RV, Mazzocca AD, Grady-Benson JC, et al. Biomechanical comparison of patellar tendon repairs in a cadaver model. Am J Sports Med 2002;30:469–473.



If you find an error or have any questions, please email us at admin@doctorlib.info. Thank you!