Surgical Treatment of Combined ACL and Medial-Sided Knee Injuries: Acute and Chronic
10.13 Operative Strategy for Acute Medial Ligamentous Repair
Operative strategy and sequence of repair or reconstruction is similar for acute and chronic injuries. Progression of anatomical restoration will proceed from deeper structures to super fi cial [ 1, 31 ] . Deepest layers consist of the menis- cofemoral and meniscotibial ligaments and the associated attachment to the medial meniscus, which is repaired if disrupted.
Fig. 10.9 (A) sMCL tibial attachment, (B) sMCL femoral attachment, (C) MPFL, (D) infrapatellar branch of saphenous nerve, (a) surgical explo- ration of medial-sided knee injury. (b) traction suture placed in MPFL in preparation for pull-through repair
Fig. 10.10 Medial structures after direct repair of sMCL, MPFL, POL, and medial retinaculum
The intermediate layer consists of the POL and semimembranosus attachments (direct and anterior arm) followed by the super fi cial layer, consisting of the sMCL.
We use as limited and focused an incision as possible based upon the MRI fi ndings, but the exposure will need to be suf fi cient to allow assessment of all injured regions, particularly the sMCL attachment sites, posteromedial capsule, and semimembrano- sus tendon. Meticulous soft tissue dissection is performed to minimize the risk of injury to the saphenous nerve and sartorial and infrapatellar branches [ 32, 33 ] . The sartorial fascia is incised anterior to the medial epicondyle and the underlying gracilis and semitendinosus tendons. The pes tendons are retracted posteriorly to allow visualization of the sMCL on the tibial surface.
Identi fi cation of all major structures and their attachment sites is performed as there can be both interstitial injury as well as disruption of the femoral or tibial attachment sites. Repair is performed from deep progressing towards super fi cial layers. This is performed using both absorbable and nonabsorbable suture material. Absorbable suture anchors are considered for repair of bony attachments of some of the deeper structures such as the meniscofemoral ligament or anterior arm of the semimembranosus tendon (Figs. 10.9 , 10.10 , 10.11 , and 10.12 ).
Avulsion of the direct semimembranosus attachment site can be repaired by placement of locking Krackow sutures through the tendon and placement of intraosseous bone tunnels from anterior to posterior, pulling the sutures out of the anteromedial aspect of the tibia and tying this over the anterior cortex or a small button. Pull-through suture technique (Fig. 10.13 ) can also be considered for femoral avulsions of the sMCL, POL, or MPFL. Locking sutures may be placed in the structure and a Beath pin passed from medial to lateral, tensioning the sutures on the lateral cortex and tying these over the bony cortex or a small button. This technique is preferred over use of suture anchors, if possible, secondary to the secure hold on the avulsed structure obtained with locking sutures and the ability to more securely tension the structure with this technique. If two or more sutures are to be passed, place all the Beath pins in their respective positions in the condyle and then drill them all the way across, as sequentially placing the pins and passing sutures can potentially lacerate previously passed sutures. We typically place sutures into the avulsed structures fi rst followed by progressive repair from deep towards super fi cial. The sMCL is tensioned at approximately 25° of fl exion. The POL is tensioned at approximately 10–20° of knee fl exion, to avoid overconstraining the knee and result in loss of terminal extension. Plication of the POL is also typically needed with direct suture repair of the
Fig. 10.11 Intraoperative image of left knee demon- strating avulsion of the sMCL off femoral attachment site, medial retinaculum tear, MPFL avulsion, and avulsion of meniscofemoral ligament
Fig. 10.12 Intraoperative photograph of a left knee demonstrating the disruption of the medial retinaculum including the MPFL and the dMCL
anterior portion of the POL to the posterior aspect of the sMCL. Several sutures may be placed and stability is assessed.
Tension is applied to the sutures in approximately 20° of fl exion, the knee was then brought into full extension to verify that there is no loss of terminal extension and adjustment of the tension and/or number of sutures is performed [ 4, 10, 31 ] . The knee is taken through a full range of motion on the table prior to closure to verify joint motion is not overconstrained. If there is MPFL or medial retinacular disruption, this is repaired at approximately 20° of fl exion to also avoid overconstraining of the patellofemoral joint.
The patient is also consented for potential use of allograft tissue in a rare case that ligamentous disruption is so severe that it precludes adequate direct repair. Limited repair may need to be considered with reconstruction of the sMCL and/or POL as described in the next section.
The sartorial fascia is loosely repaired. Hemostasis is veri fi ed. Subcutaneous closure is performed to minimize dead space and potential subsequent hematoma. The patient is placed into a compression dressing with cotton and Ace wraps followed by a bivalved cylinder cast in full extension. We typically initiate early immediate range of motion under the guidance of the physical therapist. The bivalved cylinder cast is used for the initial 3 weeks with subsequent transition to a hinged range of motion knee brace, as swelling subsides.